Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surfa...Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surface is covered with water, there is inadequacy of freshwater in most parts of the world. Hence, splitting seawater instead of freshwater could be a truly sustainable alternative. However, direct seawater splitting faces challenges because of the complex composition of seawater. The composition, and hence, the local chemistry of seawater may vary depending on its origin, and in most cases, tracking of the side reactions and standardizing and customizing the catalytic process will be an extra challenge. The corrosion of catalysts and competitive side reactions due to the presence of various inorganic and organic pollutants create challenges for developing stable electro-catalysts. Hence, seawater splitting generally involves a two-step process, i.e., purification of seawater using reverse osmosis and then subsequent fresh water splitting. However, this demands two separate chambers and larger space, and increases complexity of the reactor design. Recently, there have been efforts to directly split seawater without the reverse osmosis step. Herein, we represent the most recent innovative approaches to avoid the two-step process, and compare the potential application of membrane-assisted and membrane-less electrolyzers in direct seawater splitting(DSS). We particularly discuss the device engineering, and propose a novel electrolyzer design strategies for concentration gradient based membrane-less microfluidic electrolyzer.展开更多
The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous comp...The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous composite(Ru/HfO_(2)-NC)with Ru/HfO2nanoparticles nested in nitrogen-doped porous carbon via a zeolitic imidazole frameworks-assisted(ZIF)co-precipitation and calcination approach.In particular,ZIF guides an in-situ construction of nested configuration and confines the scattered nanoparticles.Strikingly,Ru/HfO_(2)-NC exhibits unusual ORR activity,superb durability,and methanol tolerance in0.1 M KOH solution with high half-wave potential(E1/2)of 0.83 V and follows a near-4e-reaction pathway.Additionally,the ZAB assembled with cathodic Ru/HfO_(2)-NC outputs a power density of 157.3 m W cm^(-2),a specific capacity of 775 mA h g-1Zn,and a prolonged lifespan of 258 h at 5 mA cm^(-2).Meanwhile,the catalyst has demonstrated potential applicability in flexible ZAB.As suggested by experimental results and density functional theory(DFT)analysis,the remarkable property possibly originated from the optimization of the adsorption and desorption of reactive intermediates caused by the reconfiguration of the electronic structure between Ru and HfO_(2).展开更多
Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy ...Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy of dysprosium(Dy) doping,using the unique 4f orbitals of this rare earth element to enhance electrocatalytic activity of MOFs.Our method involves constructing Dy-doped Ni-MOF(Dy@Ni-MOF) nanoneedles on carbon cloth via a Dy-induced valence electronic perturbation approach.Experiments and density functional theory(DFT) calculations reveal that Dy doping can effectively modify the electronic structure of the Ni active centers and foster a strong electronic interaction between Ni and Dy.The resulting benefits include a reduced work function and a closer proximity of the d-band center to the Fermi level,which is conducive to improving electrical conductivity and promoting the adsorption of oxygen-containing intermediates.Furthermore,the Dy@Ni-MOF achieves superhydrophilicity,ensuring effective electrolyte contact and thus accelerating reaction kinetics,Ex-situ and in-situ analysis results manifest Dy_(2)O_(3)/NiOOH as the actual active species.Therefore,Dy@Ni-MOF shows impressive OER performance,significantly surpassing Ni-MOF.Besides,the overall water splitting device with Dy@NiMOF as an anode delivers a low cell voltage of 1.51 V at 10 mA cm^(-2) and demonstrates long-term stability for 100 h,positioning it as a promising substitute for precious metal catalysts.展开更多
The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving c...The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.展开更多
Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such ...Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such as Fischer-Tropsch synthesis(FTS).Herein,we engineered ruthenium(Ru)FTS catalysts supported on N-doped carbon overlayers on TiO_(2)nanoparticles.By regulating the carbonization temperatures,we successfully controlled the types and contents of N dopants to identify their impacts on metal-support interactions(MSI).Our fi ndings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species.Moreover,pyridinic N demonstrates the highest electron-donating ability,followed by pyrrolic N and graphitic N.In addition to realizing excellent catalytic stability,strengthening the interaction between Ru sites and N dopants increases the Ru^(0)/Ru^(δ+)ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO.Consequently,it improves the catalyst’s overall performance,encompassing intrinsic and apparent activities,as well as its ability for carbon chain growth.Accordingly,the as-synthesized Ru/TiO_(2)@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C_(5+)time yield of 219.4 mol CO/(mol Ru·h)and C_(5+)selectivity of 85.5%.展开更多
We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of differ...We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of different isomers of Ge_(n+1) clusters with n = 1–20 atoms. By considering a large number of structures for each cluster size, the lowest-energy isomers are determined. The lowest-energy isomers reveal three-dimensional structures starting from n = 5. Their relative stability versus atomic size is examined based on the calculated binding energy, fragmentation energy, and second-order difference of energy. Doping Ge_(n+1) clusters with one As atom does not improve their stability. The electronic properties as a function of the atomic size are also discussed from the calculated HOMO–LUMO energy gap, vertical ionization potential, vertical electron affinity, and chemical hardness. The obtained results are significantly affected by the inclusion of one As atom into a Gen cluster.展开更多
Progress in the design and fabrication of ultraviolet and deep-ultraviolet groupⅢ–nitride optoelectronic devices,based on aluminum gallium nitride and boron nitride and their alloys,and the heterogeneous integration...Progress in the design and fabrication of ultraviolet and deep-ultraviolet groupⅢ–nitride optoelectronic devices,based on aluminum gallium nitride and boron nitride and their alloys,and the heterogeneous integration with two-dimensional and oxide-based materials is reviewed.We emphasize wide-bandgap nitride compound semiconductors(i.e.,(B,Al,Ga)N)as the deep-ultraviolet materials of interest,and two-dimensional materials,namely graphene,two-dimensional boron nitride,and two-dimensional transition metal dichalcogenides,along with gallium oxide,as the hybrid integrated materials.We examine their crystallographic properties and elaborate on the challenges that hinder the realization of efficient and reliable ultraviolet and deep-ultraviolet devices.In this article we provide an overview of aluminum nitride,sapphire,and gallium oxide as platforms for deep-ultraviolet optoelectronic devices,in which we criticize the status of sapphire as a platform for efficient deep-ultraviolet devices and detail advancements in device growth and fabrication on aluminum nitride and gallium oxide substrates.A critical review of the current status of deep-ultraviolet light emission and detection materials and devices is provided.展开更多
Classical continuum mechanics which leads to a local continuum model,encounters challenges when the discontinuity appears,while peridynamics that falls into the category of nonlocal continuum mechanics suffers from a ...Classical continuum mechanics which leads to a local continuum model,encounters challenges when the discontinuity appears,while peridynamics that falls into the category of nonlocal continuum mechanics suffers from a high computational cost.A hybrid model coupling classical continuum mechanics with peridynamics can avoid both disadvantages.This paper describes the hybrid model and its adaptive coupling approach which dynamically updates the coupling domains according to crack propagations for brittle materials.Then this hybrid local/nonlocal continuum model is applied to fracture simulation.Some numerical examples like a plate with a hole,Brazilian disk,notched plate and beam,are performed for verification and validation.In addition,a peridynamic software is introduced,which was recently developed for the simulation of the hybrid local/nonlocal continuum model.展开更多
Diblock copolymers polystyrene-block-polyvinyltriethoxysilane(PS-b-PVTES) were synthesized via atom transfer radical polymerization(ATRP), which self-assembled into spherical micelles in solvent of THF-methanol mixtur...Diblock copolymers polystyrene-block-polyvinyltriethoxysilane(PS-b-PVTES) were synthesized via atom transfer radical polymerization(ATRP), which self-assembled into spherical micelles in solvent of THF-methanol mixtures. The self-assembled micelles were immobilized by cross-linking reaction of VTES in a shell layer of micelles. The chemical structures of block copolymers and morphology of micelles were characterized in detail. It was found that the size of immobilized micelles was strongly affected by the copolymer concentration, composition of mixture solvent, and block ratios.展开更多
Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolys...Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolysis approach to obtain highly dispersed Ru nanoparticles immobilized on the vacancy-rich Ni-NiO@C hollow microsphere(Ru/Ni-NiO@C).Fine annealing at 400°C introduces nickel and oxygen vacancies on Ru/Ni-NiO@C surface,resulting in an improved electrical conductivity and rapid mass-charge transfer efficiency.Ru/Ni-NiO@C with a hollow micro/nanostructure and interconnected meso-porosity favors the maximal exposure of abundant active sites and elevation of hydrogen oxidation reaction(HOR)activity.Experimental results and density functional theory(DFT)calculations reveal that an electronic effect between Ru and Ni-NiO@C,in conjunction with nickel/oxygen vacancies in the NiO species could synergistically optimize hydrogen binding energy(HBE)and hydroxide binding energy(OHBE).The HBE and OHBE optimizations thus created confer Ru/Ni-NiO@C with a mass activity over 7.75 times higher than commercial Pt/C.Our work may provide a constructive route to make a breakthrough in elevating the hydrogen electrocatalytic performance.展开更多
Constructing a low cost,and high-efficiency oxygen evolution reaction(OER)electrocatalyst is of great significance for improving the performance of alkaline electrolyzer,which is still suffering from highenergy consum...Constructing a low cost,and high-efficiency oxygen evolution reaction(OER)electrocatalyst is of great significance for improving the performance of alkaline electrolyzer,which is still suffering from highenergy consumption.Herein,we created a porous iron phosphide and tungsten oxide self-supporting electrocatalyst with oxygen-containing vacancies on foam nickel(Fe_(2)P-WO_(2.92)/NF)through a facile insitu growth,etching and phosphating strategies.The sequence-controllable strategy will not only generate oxygen vacancies and improve the charge transfer between Fe_(2)P and WO_(2.92) components,but also improve the catalyst porosity and expose more active sites.Electrochemical studies illustrate that the Fe_(2)P-WO_(2.92)/NF catalyst presents good OER activity with a low overpotential of 267 mV at 100 mA cm^(-2),a small Tafel slope of 46.3 mV dec^(-1),high electrical conductivity,and reliable stability at high current density(100 mA cm^(-2) for over 60 h in 1.0 M KOH solution).Most significantly,the operating cell voltage of Fe_(2)P-WO_(2.92)/NF‖Pt/C is as low as 1.90 V at 400 mA cm^(-2) in alkaline condition,which is one of the lowest reported in the literature.The electrocatalytic mechanism shows that the oxygen vacancies and the synergy between Fe_(2)P and WO_(2.92) can adjust the electronic structure and provide more reaction sites,thereby synergistically increasing OER activity.This work provides a feasible strategy to fabricate high-efficiency and stable non-noble metal OER electrocatalysts on the engineering interface.展开更多
Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons...Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities.Nevertheless,most lignocellulose biomasses lack heteroatoms,making it a challenge to design highly heteroatom-doped carbons(>10 at%).Herein,we report a new preparation strategy for amorphous carbon anodes.Nitrogen/sulfur co-doped lignin-derived porous carbons(NSLPC)with ultra-high nitrogen doping levels(21.6 at%of N and 0.8 at%of S)from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy.This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product,which induces the formation of high heteroatom doping in the obtained NSLPC.This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+and improved kinetics.The NSLPC anode delivered a high reversible capacity of 419 mAh g^(-1)and superior cycling stability(capacity retention of 96.6%at 1 A g^(-1)for 1000 cycles).Potassiumion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability(91%capacity retention for 2000 cycles)and a high energy density of 71 Wh kg^(-1)at a power density of 92 W kg^(-1).展开更多
Aluminum-based alloys play a key role in modern engineering and are widely used in construction components in aircraft, automobiles and other means of transportation due to their light weight and superior mechanical p...Aluminum-based alloys play a key role in modern engineering and are widely used in construction components in aircraft, automobiles and other means of transportation due to their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. An improvement of an Al-based alloy has been performed based on the understanding of the relationships among compositions, processing, microstructural characteristics and properties. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu alloys during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Investigation of the fine scale segregation effects of dilute solutes in aluminum alloys which were experienced different heat treatments by using atom probe tomography has been achieved. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160°C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160°C) induces increasing on the number density of the Li clusters and hence increase number of precipitated particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus the results contribute to the understanding of Al-alloy design.展开更多
Graphene is a two-dimensional crystal of carbon atoms arranged in a honeycomb lattice. It is a zero band gap semimetal with very unique physical and chemical properties which make it useful for many applications such ...Graphene is a two-dimensional crystal of carbon atoms arranged in a honeycomb lattice. It is a zero band gap semimetal with very unique physical and chemical properties which make it useful for many applications such as ultra-high-speed field-effect transistors, p-n junction diodes, terahertz oscillators, and low-noise electronic, NEMS and sensors. When the high quality mass production of this nanomaterial is still a big challenge, we developed a process which will be an important step to achieve this goal. Atomic Force Microscopy, Scanning Electron Microscopy, Scanning tunneling microscopy, High Resolution Transmission Electron Microscopy, X-Ray Diffraction, Raman spectroscopy, Energy Dispersive X-ray system were investigated to characterize and examine the quality of this product.展开更多
In the last few decades,deep learning(DL)has afforded solutions to macroscopic problems in petroleum engineering,but mechanistic problems at the microscale have not benefited from it.Mechanism studies have been the st...In the last few decades,deep learning(DL)has afforded solutions to macroscopic problems in petroleum engineering,but mechanistic problems at the microscale have not benefited from it.Mechanism studies have been the strong demands for the emerging projects,such as the gas storage and hydrate production,and for some problems encountered in the storage process,which are common found as the chemical interaction between injected gas and mineral,and the formation of hydrate.Emerging advances in DL technology enable solving molecular dynamics(MD)with quantum accuracy.The conventional quantum chemical method is computational expensive,whereas the classical MD method cannot guarantee high accuracy because of its empirical force field parameters.With the help of the DL force field,precision at the quantum chemistry level can be achieved in MD.Moreover,the DL force field promotes the computational speed compared with first-principles calculations.In this review,the basic knowledge of the molecular force field and deep neural network(DNN)is first introduced.Then,three representative opensource packages relevant to the DL force field are introduced.As the most common components in the development of oil and gas reservoirs,water and methane are studied from the aspects of computational efficiency and chemical reaction respectively,providing the foundation of oil and gas researches.However,in the oil and gas problems,the complex molecular topo structures and various element types set a high challenge for the DL techniques in MD.Regarding the computational efficiency,it needs improvement via GPU and parallel accelerations to compete with classical MD.Even with such difficulties,the booming of this technique in the area of petroleum engineering can be predictable.展开更多
In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burn...In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.展开更多
Direct photon to chemical energy conversion using semiconductor–electrocatalyst–electrolyte interfaces has been extensively investigated for more than a half century. Many studies have focused on screening materials...Direct photon to chemical energy conversion using semiconductor–electrocatalyst–electrolyte interfaces has been extensively investigated for more than a half century. Many studies have focused on screening materials for efficient photocatalysis. Photocatalytic efficiency has been improved during this period but is not sufficient for industrial commercialization. Detailed elucidation on the photocatalytic water splitting process leads to consecutive six reaction steps with the fundamental parameters involved: The photocatalysis is initiated involving photophysics derived from various semiconductor properties(1: photon absorption, 2: exciton separation). The generated charge carriers need to be transferred to surfaces effectively utilizing the interfaces(3: carrier diffusion, 4: carrier transport). Consequently, electrocatalysis finishes the process by producing products on the surface(5: catalytic efficiency, 6: mass transfer of reactants and products). Successful photocatalytic water splitting requires the enhancement of efficiency at each stage. Most critically, a fundamental understanding of the interfacial phenomena is highly desired for establishing "photocatalysis by design" concepts, where the kinetic bottleneck within a process is identified by further improving the specific properties of photocatalytic materials as opposed to blind material screening. Theoretical modeling using the identified quantitative parameters can effectively predict the theoretically attainable photon-conversion yields. This article provides an overview of the state-of-the-art theoretical understanding of interfacial problems mainly developed in our laboratory.Photocatalytic water splitting(especially hydrogen evolution on metal surfaces) was selected as a topic,and the photophysical and electrochemical processes that occur at semiconductor–metal, semiconductor–electrolyte and metal–electrolyte interfaces are discussed.展开更多
A series of graphitic-C_3N_4/ZnS(g-C_3N_4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. Th...A series of graphitic-C_3N_4/ZnS(g-C_3N_4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C_3N_4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, gC_3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C_3N_4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C_3N_4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C_3N_4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.展开更多
Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces...Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces the significance of the tuning of electronic structure,where modifying the electronic structure of the electrocatalysts could generate active sites having optimal adsorption energy with OER intermediates,and that could diminish the energy barrier for OER,and that could improve the activity for OER.Later,this paper reviews the tuning of electronic structure along with catalytic performances,synthetic methodologies,chemical properties,and DFT calculations on various nanostructured earth-abundant electrocatalysts for OER in alkaline environment.Further,this review discusses the tuning of the electronic structure of the several nanostructured earth-abundant electrocatalysts including oxide,(oxy)hydroxide,layered double hydroxide,alloy,metal phosphide/phosphate,nitride,sulfide,selenide,carbon containing materials,MOF,core-shell/hetero/hollow structured materials,and materials with vacancies/defects for OER in alkaline environment(including activity:overpotential(η)of ≤200 mV at10 m A cm^(-2);stability:≥100 h;durability:≥5000 cycles).Then,this review discusses the robust stability of the electrocatalysts for OER towards practical application.Moreover,this review discusses the in situ formation of thin layer on the catalyst surface during OER.In addition,this review discusses the influence of the adsorption energy of the OER intermediates on OER performance of the catalysts.Finally,this review summarizes the various promising strategies for tuning the electronic structure of the electrocatalysts to achieve enhanced performance for OER in alkaline environment.展开更多
Recently,there has been renewed interest in interface engineering as a means to further push the performance of perovskite solar cells closer to the Schockly-Queisser limit.Herein,for the first time we employ a multi-...Recently,there has been renewed interest in interface engineering as a means to further push the performance of perovskite solar cells closer to the Schockly-Queisser limit.Herein,for the first time we employ a multi-functional 4-chlorobenzoic acid to produce a self-assembled monolayer on a perovskite surface.With this interlayer we observe passivation of perovskite surface defects and a significant suppression of non-radiative charge recombination.Furthermore,at the surface of the interlayer we observe,charge dipoles which tune the energy level alignment,enabling a larger energetic driving force for hole extraction.The perovskite surface becomes more hydrophilic due to the presence of the interlayer.Consequently,we observe an improvement in open-circuit voltage from 1.08 to 1.16 V,a power conversion efficiency improvement from 18%to 21%and an improved stability under ambient conditions.Our work highlights the potential of SAMs to engineer the photo-electronic properties and stability of perovskite interfaces to achieve high-performance light harvesting devices.展开更多
基金King Abdullah University of Science and Technology for funding through the funding grant (BAS/1/1413-01-01)the Engineering and Physical Sciences Research Council (EPSRC,EP/V027433/1)+1 种基金the Royal Society (RGSR1211080IESR2212115)。
文摘Electrocatalytic splitting of water by means of renewable energy as the electricity supply is one of the most promising methods for storing green renewable energy as hydrogen. Although two-thirds of the earth’s surface is covered with water, there is inadequacy of freshwater in most parts of the world. Hence, splitting seawater instead of freshwater could be a truly sustainable alternative. However, direct seawater splitting faces challenges because of the complex composition of seawater. The composition, and hence, the local chemistry of seawater may vary depending on its origin, and in most cases, tracking of the side reactions and standardizing and customizing the catalytic process will be an extra challenge. The corrosion of catalysts and competitive side reactions due to the presence of various inorganic and organic pollutants create challenges for developing stable electro-catalysts. Hence, seawater splitting generally involves a two-step process, i.e., purification of seawater using reverse osmosis and then subsequent fresh water splitting. However, this demands two separate chambers and larger space, and increases complexity of the reactor design. Recently, there have been efforts to directly split seawater without the reverse osmosis step. Herein, we represent the most recent innovative approaches to avoid the two-step process, and compare the potential application of membrane-assisted and membrane-less electrolyzers in direct seawater splitting(DSS). We particularly discuss the device engineering, and propose a novel electrolyzer design strategies for concentration gradient based membrane-less microfluidic electrolyzer.
基金supported by the National Natural Science Foundation of China(21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001)+1 种基金the Project of HighLevel Talents of Guangxi(F-KA18015)Guangxi Technology Base and Talent Subject(GUIKE AD18126001,GUIKE AD20297039)。
文摘The construction of oxide/metal composite catalysts is a competent means of exploiting the electronic interactions between oxide/metal to enhance catalytic activity.In this work,we construct a novel heterogeneous composite(Ru/HfO_(2)-NC)with Ru/HfO2nanoparticles nested in nitrogen-doped porous carbon via a zeolitic imidazole frameworks-assisted(ZIF)co-precipitation and calcination approach.In particular,ZIF guides an in-situ construction of nested configuration and confines the scattered nanoparticles.Strikingly,Ru/HfO_(2)-NC exhibits unusual ORR activity,superb durability,and methanol tolerance in0.1 M KOH solution with high half-wave potential(E1/2)of 0.83 V and follows a near-4e-reaction pathway.Additionally,the ZAB assembled with cathodic Ru/HfO_(2)-NC outputs a power density of 157.3 m W cm^(-2),a specific capacity of 775 mA h g-1Zn,and a prolonged lifespan of 258 h at 5 mA cm^(-2).Meanwhile,the catalyst has demonstrated potential applicability in flexible ZAB.As suggested by experimental results and density functional theory(DFT)analysis,the remarkable property possibly originated from the optimization of the adsorption and desorption of reactive intermediates caused by the reconfiguration of the electronic structure between Ru and HfO_(2).
基金supported by the National Natural Science Foundation of China(52363028,21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001)the Guangxi Technology Base and Talent Subject(GUIKE AD18126001,GUIKE AD20297039)。
文摘Tackling the problem of poor conductivity and catalytic stability of pristine metal-organic frameworks(MOFs) is crucial to improve their oxygen evolution reaction(OER) performance.Herein,we introduce a novel strategy of dysprosium(Dy) doping,using the unique 4f orbitals of this rare earth element to enhance electrocatalytic activity of MOFs.Our method involves constructing Dy-doped Ni-MOF(Dy@Ni-MOF) nanoneedles on carbon cloth via a Dy-induced valence electronic perturbation approach.Experiments and density functional theory(DFT) calculations reveal that Dy doping can effectively modify the electronic structure of the Ni active centers and foster a strong electronic interaction between Ni and Dy.The resulting benefits include a reduced work function and a closer proximity of the d-band center to the Fermi level,which is conducive to improving electrical conductivity and promoting the adsorption of oxygen-containing intermediates.Furthermore,the Dy@Ni-MOF achieves superhydrophilicity,ensuring effective electrolyte contact and thus accelerating reaction kinetics,Ex-situ and in-situ analysis results manifest Dy_(2)O_(3)/NiOOH as the actual active species.Therefore,Dy@Ni-MOF shows impressive OER performance,significantly surpassing Ni-MOF.Besides,the overall water splitting device with Dy@NiMOF as an anode delivers a low cell voltage of 1.51 V at 10 mA cm^(-2) and demonstrates long-term stability for 100 h,positioning it as a promising substitute for precious metal catalysts.
基金financial support from the King Abdullah University of Science and Technology(KAUST).
文摘The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.
基金the financial support from by the National Key Research and Development Program of China(No.2022YFB4101800)National Natural Science Foundation of China(No.22278298)Program for Introducing Talents of Discipline to Universities of China(No.BP0618007).
文摘Nitrogen(N)-doped carbon materials as metal catalyst supports have attracted signifi cant attention,but the eff ect of N dopants on catalytic performance remains unclear,especially for complex reaction processes such as Fischer-Tropsch synthesis(FTS).Herein,we engineered ruthenium(Ru)FTS catalysts supported on N-doped carbon overlayers on TiO_(2)nanoparticles.By regulating the carbonization temperatures,we successfully controlled the types and contents of N dopants to identify their impacts on metal-support interactions(MSI).Our fi ndings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species.Moreover,pyridinic N demonstrates the highest electron-donating ability,followed by pyrrolic N and graphitic N.In addition to realizing excellent catalytic stability,strengthening the interaction between Ru sites and N dopants increases the Ru^(0)/Ru^(δ+)ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO.Consequently,it improves the catalyst’s overall performance,encompassing intrinsic and apparent activities,as well as its ability for carbon chain growth.Accordingly,the as-synthesized Ru/TiO_(2)@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C_(5+)time yield of 219.4 mol CO/(mol Ru·h)and C_(5+)selectivity of 85.5%.
文摘We present a systematic computational study based on the density functional theory(DFT) aiming to high light the possible effects of one As doping atom on the structural, energetic, and electronic properties of different isomers of Ge_(n+1) clusters with n = 1–20 atoms. By considering a large number of structures for each cluster size, the lowest-energy isomers are determined. The lowest-energy isomers reveal three-dimensional structures starting from n = 5. Their relative stability versus atomic size is examined based on the calculated binding energy, fragmentation energy, and second-order difference of energy. Doping Ge_(n+1) clusters with one As atom does not improve their stability. The electronic properties as a function of the atomic size are also discussed from the calculated HOMO–LUMO energy gap, vertical ionization potential, vertical electron affinity, and chemical hardness. The obtained results are significantly affected by the inclusion of one As atom into a Gen cluster.
基金financial support from the King Abdulaziz City for Science and Technology (KACST) under grant no. KACST TIC R2-FP-008partially supported by the King Abdullah University of Science and Technology (KAUST) baseline funding no. BAS/1/1614-01-01MBE equipment funding no. C/M-20000-12-001-77 and KCR/1/4055-01-01
文摘Progress in the design and fabrication of ultraviolet and deep-ultraviolet groupⅢ–nitride optoelectronic devices,based on aluminum gallium nitride and boron nitride and their alloys,and the heterogeneous integration with two-dimensional and oxide-based materials is reviewed.We emphasize wide-bandgap nitride compound semiconductors(i.e.,(B,Al,Ga)N)as the deep-ultraviolet materials of interest,and two-dimensional materials,namely graphene,two-dimensional boron nitride,and two-dimensional transition metal dichalcogenides,along with gallium oxide,as the hybrid integrated materials.We examine their crystallographic properties and elaborate on the challenges that hinder the realization of efficient and reliable ultraviolet and deep-ultraviolet devices.In this article we provide an overview of aluminum nitride,sapphire,and gallium oxide as platforms for deep-ultraviolet optoelectronic devices,in which we criticize the status of sapphire as a platform for efficient deep-ultraviolet devices and detail advancements in device growth and fabrication on aluminum nitride and gallium oxide substrates.A critical review of the current status of deep-ultraviolet light emission and detection materials and devices is provided.
基金The authors gratefully acknowledge the financial support received from KAUST baseline,the National Natural Science Foundation(11872016)the Fundamental Research Funds of Dalian University of Technology(Grant No.DUT17RC(3)092)for the completion of this work.
文摘Classical continuum mechanics which leads to a local continuum model,encounters challenges when the discontinuity appears,while peridynamics that falls into the category of nonlocal continuum mechanics suffers from a high computational cost.A hybrid model coupling classical continuum mechanics with peridynamics can avoid both disadvantages.This paper describes the hybrid model and its adaptive coupling approach which dynamically updates the coupling domains according to crack propagations for brittle materials.Then this hybrid local/nonlocal continuum model is applied to fracture simulation.Some numerical examples like a plate with a hole,Brazilian disk,notched plate and beam,are performed for verification and validation.In addition,a peridynamic software is introduced,which was recently developed for the simulation of the hybrid local/nonlocal continuum model.
基金Funded by the National Natural Science Foundation of China(Nos.51403001,20804001,20974001,21174001,51273001)the Research Fund for the Doctoral Program of Higher Education of China(No.20113401110003)"211 Project"and"Incubation Fund for Excellent Young Researcher"of Anhui University
文摘Diblock copolymers polystyrene-block-polyvinyltriethoxysilane(PS-b-PVTES) were synthesized via atom transfer radical polymerization(ATRP), which self-assembled into spherical micelles in solvent of THF-methanol mixtures. The self-assembled micelles were immobilized by cross-linking reaction of VTES in a shell layer of micelles. The chemical structures of block copolymers and morphology of micelles were characterized in detail. It was found that the size of immobilized micelles was strongly affected by the copolymer concentration, composition of mixture solvent, and block ratios.
基金supported by the National Natural Science Foundation of China(21965005)the Natural Science Foundation of Guangxi Province(2018GXNSFAA294077,2021GXNSFAA076001)+1 种基金the Project of High-Level Talents of Guangxi(F-KA18015)the Guangxi Technology Base and Talent Subject(GUIKEAD18126001,GUIKE AD20297039)。
文摘Surface vacancy defects,as the bridge between theoretical structural study and the design of heterogenous catalysts,have captured much attention.This work develops a metal-organic framework-engaged replacement-pyrolysis approach to obtain highly dispersed Ru nanoparticles immobilized on the vacancy-rich Ni-NiO@C hollow microsphere(Ru/Ni-NiO@C).Fine annealing at 400°C introduces nickel and oxygen vacancies on Ru/Ni-NiO@C surface,resulting in an improved electrical conductivity and rapid mass-charge transfer efficiency.Ru/Ni-NiO@C with a hollow micro/nanostructure and interconnected meso-porosity favors the maximal exposure of abundant active sites and elevation of hydrogen oxidation reaction(HOR)activity.Experimental results and density functional theory(DFT)calculations reveal that an electronic effect between Ru and Ni-NiO@C,in conjunction with nickel/oxygen vacancies in the NiO species could synergistically optimize hydrogen binding energy(HBE)and hydroxide binding energy(OHBE).The HBE and OHBE optimizations thus created confer Ru/Ni-NiO@C with a mass activity over 7.75 times higher than commercial Pt/C.Our work may provide a constructive route to make a breakthrough in elevating the hydrogen electrocatalytic performance.
基金supported by the National Natural Science Foundation of China(no.21965005)the Natural Science Foundation of Guangxi Province(2018GXNSFAA294077,2021GXNSFAA076001)+1 种基金the Project of High-Level Talents of Guangxi(F-KA18015)Guangxi Technology Base and Talent Subject(GUIKE AD18126001,GUIKE AD20297039)。
文摘Constructing a low cost,and high-efficiency oxygen evolution reaction(OER)electrocatalyst is of great significance for improving the performance of alkaline electrolyzer,which is still suffering from highenergy consumption.Herein,we created a porous iron phosphide and tungsten oxide self-supporting electrocatalyst with oxygen-containing vacancies on foam nickel(Fe_(2)P-WO_(2.92)/NF)through a facile insitu growth,etching and phosphating strategies.The sequence-controllable strategy will not only generate oxygen vacancies and improve the charge transfer between Fe_(2)P and WO_(2.92) components,but also improve the catalyst porosity and expose more active sites.Electrochemical studies illustrate that the Fe_(2)P-WO_(2.92)/NF catalyst presents good OER activity with a low overpotential of 267 mV at 100 mA cm^(-2),a small Tafel slope of 46.3 mV dec^(-1),high electrical conductivity,and reliable stability at high current density(100 mA cm^(-2) for over 60 h in 1.0 M KOH solution).Most significantly,the operating cell voltage of Fe_(2)P-WO_(2.92)/NF‖Pt/C is as low as 1.90 V at 400 mA cm^(-2) in alkaline condition,which is one of the lowest reported in the literature.The electrocatalytic mechanism shows that the oxygen vacancies and the synergy between Fe_(2)P and WO_(2.92) can adjust the electronic structure and provide more reaction sites,thereby synergistically increasing OER activity.This work provides a feasible strategy to fabricate high-efficiency and stable non-noble metal OER electrocatalysts on the engineering interface.
基金the financial support from the National Natural Science Foundation of China(22108044,22208061)the Research and Development Program in Key Fields of Guangdong Province(2020B1111380002)+1 种基金the Basic Research and Applicable Basic Research in Guangzhou City(202201010290)the financial support from the Guangdong Provincial Key Laboratory of Plant Resources Biorefinery(2021GDKLPRB07)。
文摘Amorphous carbons are promising anodes for high-rate potassium-ion batteries.Most low-temperature annealed amorphous carbons display unsatisfactory capacities.Heteroatom-induced defect engineering of amorphous carbons could enhance their reversible capacities.Nevertheless,most lignocellulose biomasses lack heteroatoms,making it a challenge to design highly heteroatom-doped carbons(>10 at%).Herein,we report a new preparation strategy for amorphous carbon anodes.Nitrogen/sulfur co-doped lignin-derived porous carbons(NSLPC)with ultra-high nitrogen doping levels(21.6 at%of N and 0.8 at%of S)from renewable lignin biomacromolecule precursors were prepared through a supramolecule-mediated pyrolysis strategy.This supermolecule/lignin composite decomposes forming a covalently bonded graphitic carbon/amorphous carbon intermediate product,which induces the formation of high heteroatom doping in the obtained NSLPC.This unique pyrolysis chemistry and high heteroatom doping of NSLPC enable abundant defective active sites for the adsorption of K+and improved kinetics.The NSLPC anode delivered a high reversible capacity of 419 mAh g^(-1)and superior cycling stability(capacity retention of 96.6%at 1 A g^(-1)for 1000 cycles).Potassiumion hybrid capacitors assembled by NSLPC anode exhibited excellent cycling stability(91%capacity retention for 2000 cycles)and a high energy density of 71 Wh kg^(-1)at a power density of 92 W kg^(-1).
文摘Aluminum-based alloys play a key role in modern engineering and are widely used in construction components in aircraft, automobiles and other means of transportation due to their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. An improvement of an Al-based alloy has been performed based on the understanding of the relationships among compositions, processing, microstructural characteristics and properties. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu alloys during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Investigation of the fine scale segregation effects of dilute solutes in aluminum alloys which were experienced different heat treatments by using atom probe tomography has been achieved. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160°C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160°C) induces increasing on the number density of the Li clusters and hence increase number of precipitated particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus the results contribute to the understanding of Al-alloy design.
文摘Graphene is a two-dimensional crystal of carbon atoms arranged in a honeycomb lattice. It is a zero band gap semimetal with very unique physical and chemical properties which make it useful for many applications such as ultra-high-speed field-effect transistors, p-n junction diodes, terahertz oscillators, and low-noise electronic, NEMS and sensors. When the high quality mass production of this nanomaterial is still a big challenge, we developed a process which will be an important step to achieve this goal. Atomic Force Microscopy, Scanning Electron Microscopy, Scanning tunneling microscopy, High Resolution Transmission Electron Microscopy, X-Ray Diffraction, Raman spectroscopy, Energy Dispersive X-ray system were investigated to characterize and examine the quality of this product.
基金We would like to express appreciation to the following financial support:National Natural Scientific Foundation of China(Grants No.51936001)King Abdullah University of Science and Technology(KAUST)through the grants BAS/1/1351-01,URF/1/4074-01,and URF/1/3769-01.
文摘In the last few decades,deep learning(DL)has afforded solutions to macroscopic problems in petroleum engineering,but mechanistic problems at the microscale have not benefited from it.Mechanism studies have been the strong demands for the emerging projects,such as the gas storage and hydrate production,and for some problems encountered in the storage process,which are common found as the chemical interaction between injected gas and mineral,and the formation of hydrate.Emerging advances in DL technology enable solving molecular dynamics(MD)with quantum accuracy.The conventional quantum chemical method is computational expensive,whereas the classical MD method cannot guarantee high accuracy because of its empirical force field parameters.With the help of the DL force field,precision at the quantum chemistry level can be achieved in MD.Moreover,the DL force field promotes the computational speed compared with first-principles calculations.In this review,the basic knowledge of the molecular force field and deep neural network(DNN)is first introduced.Then,three representative opensource packages relevant to the DL force field are introduced.As the most common components in the development of oil and gas reservoirs,water and methane are studied from the aspects of computational efficiency and chemical reaction respectively,providing the foundation of oil and gas researches.However,in the oil and gas problems,the complex molecular topo structures and various element types set a high challenge for the DL techniques in MD.Regarding the computational efficiency,it needs improvement via GPU and parallel accelerations to compete with classical MD.Even with such difficulties,the booming of this technique in the area of petroleum engineering can be predictable.
基金supported by the National Natural Science Foundation of China(Grant No. 51906075)Key Research and Development Program of Department of Science and Technology of Jiangxi Province(Grant No. 20223BBG74009)Science and Technology Innovation Project for Carbon Peak and Carbon Neutrality of Jiangxi Carbon Neutralization Research Center(Grant No. 2022JXST01)。
文摘In the past two decades, the oxy-fuel combustion of pulverized coal has been extensively developed, leading to the completion of several large industrial pilot oxy-fuel plants worldwide. Various types of oxy-fuel burners have been designed and tested in largescale pilot plants as key components of oxy-fuel combustion. These burners face major challenges in terms of their flame stability because of their decreasing stream momentum ratio and increasing carbon dioxide concentration. However, it offers flexibility in adjusting the oxygen concentration in each burner stream. This study aims to provide a comprehensive review of the state-of-the-art knowledge on oxy-coal burner design and operation in power plants. First, the combustion characteristics under oxy-fuel conditions are briefly introduced. Subsequently, the principal requirements and fundamental parameters of the oxy-coal burners are discussed. The development process of oxy-fuel burners is also presented. Moreover, a compatible design strategy and scaling-up techniques are described for oxy-coal burners developed by the authors over the past ten years. The performances of oxy-coal burners in three large pilot oxy-fuel plants worldwide are summarized and compared. Finally, concluding remarks are provided and potential research needs are suggested.
基金supported by funding from King Abdullah University of Science and Technology(KAUST)
文摘Direct photon to chemical energy conversion using semiconductor–electrocatalyst–electrolyte interfaces has been extensively investigated for more than a half century. Many studies have focused on screening materials for efficient photocatalysis. Photocatalytic efficiency has been improved during this period but is not sufficient for industrial commercialization. Detailed elucidation on the photocatalytic water splitting process leads to consecutive six reaction steps with the fundamental parameters involved: The photocatalysis is initiated involving photophysics derived from various semiconductor properties(1: photon absorption, 2: exciton separation). The generated charge carriers need to be transferred to surfaces effectively utilizing the interfaces(3: carrier diffusion, 4: carrier transport). Consequently, electrocatalysis finishes the process by producing products on the surface(5: catalytic efficiency, 6: mass transfer of reactants and products). Successful photocatalytic water splitting requires the enhancement of efficiency at each stage. Most critically, a fundamental understanding of the interfacial phenomena is highly desired for establishing "photocatalysis by design" concepts, where the kinetic bottleneck within a process is identified by further improving the specific properties of photocatalytic materials as opposed to blind material screening. Theoretical modeling using the identified quantitative parameters can effectively predict the theoretically attainable photon-conversion yields. This article provides an overview of the state-of-the-art theoretical understanding of interfacial problems mainly developed in our laboratory.Photocatalytic water splitting(especially hydrogen evolution on metal surfaces) was selected as a topic,and the photophysical and electrochemical processes that occur at semiconductor–metal, semiconductor–electrolyte and metal–electrolyte interfaces are discussed.
基金supported by the National Nature Science Foundations of China (Grant no. 51372212)
文摘A series of graphitic-C_3N_4/ZnS(g-C_3N_4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C_3N_4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, gC_3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C_3N_4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C_3N_4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C_3N_4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.
基金supported by the King Abdullah University of Science and Technology(KAUST)。
文摘Tuning the electronic structure of the electrocatalysts for oxygen evolution reaction(OER)is a promising way to achieve efficient alkaline water splitting for clean energy production(H2).At first,this paper introduces the significance of the tuning of electronic structure,where modifying the electronic structure of the electrocatalysts could generate active sites having optimal adsorption energy with OER intermediates,and that could diminish the energy barrier for OER,and that could improve the activity for OER.Later,this paper reviews the tuning of electronic structure along with catalytic performances,synthetic methodologies,chemical properties,and DFT calculations on various nanostructured earth-abundant electrocatalysts for OER in alkaline environment.Further,this review discusses the tuning of the electronic structure of the several nanostructured earth-abundant electrocatalysts including oxide,(oxy)hydroxide,layered double hydroxide,alloy,metal phosphide/phosphate,nitride,sulfide,selenide,carbon containing materials,MOF,core-shell/hetero/hollow structured materials,and materials with vacancies/defects for OER in alkaline environment(including activity:overpotential(η)of ≤200 mV at10 m A cm^(-2);stability:≥100 h;durability:≥5000 cycles).Then,this review discusses the robust stability of the electrocatalysts for OER towards practical application.Moreover,this review discusses the in situ formation of thin layer on the catalyst surface during OER.In addition,this review discusses the influence of the adsorption energy of the OER intermediates on OER performance of the catalysts.Finally,this review summarizes the various promising strategies for tuning the electronic structure of the electrocatalysts to achieve enhanced performance for OER in alkaline environment.
基金supported by the National Natural Science Foundation of China(Grant Nos.52073115,61874048,12073009)the Project of Science and Technology Development Plan of Jilin Province(Grant No.20200201085JC).
文摘Recently,there has been renewed interest in interface engineering as a means to further push the performance of perovskite solar cells closer to the Schockly-Queisser limit.Herein,for the first time we employ a multi-functional 4-chlorobenzoic acid to produce a self-assembled monolayer on a perovskite surface.With this interlayer we observe passivation of perovskite surface defects and a significant suppression of non-radiative charge recombination.Furthermore,at the surface of the interlayer we observe,charge dipoles which tune the energy level alignment,enabling a larger energetic driving force for hole extraction.The perovskite surface becomes more hydrophilic due to the presence of the interlayer.Consequently,we observe an improvement in open-circuit voltage from 1.08 to 1.16 V,a power conversion efficiency improvement from 18%to 21%and an improved stability under ambient conditions.Our work highlights the potential of SAMs to engineer the photo-electronic properties and stability of perovskite interfaces to achieve high-performance light harvesting devices.