Potential industrial applications of photo/electrocatalysis: Recent progress and future challenges

Nowadays,the rapid development of the social economy inevitably leads to global energy and environmental crisis.For this reason,more and more scholars focus on the development of photocatalysis and/or electrocatalysis technology for the advantage in the sustainable production of high-value-added products,and the high efficiency in pollutants remediation.Although there is plenty of outstanding research has been put forward continuously,most of them focuses on catalysis performance and reaction mechanisms in laboratory conditions.Realizing industrial application of photo/electrocatalytic processes is still a challenge that needs to be overcome by social demand.In this regard,this review comprehensively summarized several explorations in thefield of photo/electrocatalytic reduction towards potential industrial applications in recent years.Special attention is paid to the successful attempts and the current status of photo/electrocatalytic water splitting,carbon dioxide conversion,resource utilization from waste,etc.,by using advanced reactors.The key problems and challenges of photo/electrocatalysis in future industrial practice are also discussed,and the possible development directions are also pointed out from the industry view.

Single-atom Pt on carbon nanotubes for selective electrocatalysis

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOR).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox reaction.Characterizations via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the Pt.The electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the electrocatalyst.The single-atom samples showed higher HOR activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating range.The selective activity toward HOR arose as the main fingerprint of the catalyst confinement in the SWCNTs.

Differences and Similarities of Photocatalysis and Electrocatalysis in Two-Dimensional Nanomaterials:Strategies,Traps,Applications and Challenges

Photocatalysis and electrocatalysis have been essential parts of electrochemical processes for over half a century.Recent progress in the controllable synthesis of 2D nanomaterials has exhibited enhanced catalytic performance compared to bulk materials.This has led to significant interest in the exploitation of 2D nanomaterials for catalysis.There have been a variety of excellent reviews on 2D nanomaterials for catalysis,but related issues of differences and similarities between photocatalysis and electrocatalysis in 2D nanomaterials are still vacant.Here,we provide a comprehensive overview on the differences and similarities of photocatalysis and electrocatalysis in the latest 2D nanomaterials.Strategies and traps for performance enhancement of 2D nanocatalysts are highlighted,which point out the differences and similarities of series issues for photocatalysis and electrocatalysis.In addition,2D nanocatalysts and their catalytic applications are discussed.Finally,opportunities,challenges and development directions for 2D nanocatalysts are described.The intention of this review is to inspire and direct interest in this research realm for the creation of future 2D nanomaterials for photocatalysis and electrocatalysis.

Single Nanobubble Formation on Au Nanoelectrodes and Au@WS_(2)Nanoelectrodes:Voltammetric Analysis and Electrocatalysis

Taking advantage of the extremely small size of the gold nanodisk electrode,the single hydrogen nanobubble generated on the surface of the nanoelectrode was studied to evaluate its hydrogen evolution performance.It was found that compared with the bare gold nanodisk electrode,the bubble formation potential of the gold nanodisk electrode modified with tungsten disulfide quantum dots(WS_(2)QDs)on the surface was more positive,indicating that its hydrogen evolution activity was higher.Microdynamic model analysis shows that the average standard rate constant of the rate-determining step of the hydrogen evolution reaction of gold nanoelectrodes modified with WS_(2)QDs is approximately 12 times larger than that of gold nanoelectrodes.This work based on the formation of nanobubbles provides new ideas for the design and performance evaluation of hydrogen evolution reaction catalysts.

Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work.

Covalent organic frameworks/carbon nanotubes composite with cobalt(II)pyrimidine sites for bifunctional oxygen electrocatalysis

With characteristics and advantages of functional composite materials,they are commendably adopted in numerous fields especially in oxygen electrocatalysis,which is due to the significant synergies between various components.Herein,a novel bifunctional oxygen electrocatalyst(Co-CNT@COF-Pyr)has been synthesized through in-situ growth of covalent organic frameworks(COFs)layers on the outer surface of highly conductive carbon nanotubes(CNTs)followed by coordination with Co(Ⅱ).For electrocatalytic OER,Co-CNT@COF-Pyr reveals a low overpotential(438 mV)in alkaline electrolyte(1.0 M aqueous solution of KOH)with a current density of 10 mA cm^(-2),which is comparable to most discovered COF-based catalysts.For electrocatalytic ORR,CoCNT@COF-Pyr exhibits a low H_(2)O_(2) yield range(9.0%-10.1%)and a reaction pathway close to 4e^(-)(n=3.82-3.80)in alkaline electrolyte(0.1 M aqueous solution of KOH)within the test potential range of 0.1-0.6 V vs.RHE,which is superior to most reported COF-based catalysts.Hence,this research could not only offer an innovative insight into the construction of composites,but also facilitate the practical application of renewable fuel cells,closed water cycle,and rechargeable metal-air batteries.

A post-modification strategy to precisely construct dual-atom sites for oxygen reduction electrocatalysis

Dual-atom catalysts(DACs) afford promising potential for oxygen reduction electrocatalysis due to their high atomic efficiency and high intrinsic activity.However,precise construction of dual-atom sites remains a challenge.In this work,a post-modification strategy is proposed to precisely fabricate DACs for oxygen reduction electrocatalysis.Concretely,a secondary metal precursor is introduced to the primary single-atom sites to introduce direct metal-metal interaction,which ensures the formation of desired atom pair structure during the subsequent pyrolysis process and allows for successful construction of DACs.The as-prepared FeCo-NC DAC exhibits superior oxygen reduction electrocatalytic activity with a half-wave potential of 0,91 V vs.reversible hydrogen electrode.Zn-air batteries equipped with the FeCo-NC DAC demonstrate higher peak power density than those with the Pt/C benchmark.More importantly,this post-modification strategy is demonstrated universal to achieve a variety of dual-atom sites.This work presents an effective synthesis methodology for precise construction of catalytic materials and propels their applications in energy-related devices.

Hydrogen Spillover Effect in Electrocatalysis:Delving into the Mysteries of the Atomic Migration

Hydrogen spillover effect has recently garnered a lot of attention in the field of electrocatalytic hydrogen evolution reactions.A new avenue for understanding the dynamic behavior of atomic migration in which hydrogen atoms moving on a catalyst surface was opened up by the setup of the word"hydrogen spillover."However,there is currently a dearth of thorough knowledge regarding the hydrogen spillover effect.Currently,the advancement of sophisticated characterization procedures offers progressively useful information to enhance our grasp of the hydrogen spillover effect.The understanding of material fabrication for hydrogen spillover effect has erupted.Considering these factors,we made an effort to review most of the articles published on the hydrogen spillover effect and carefully analyzed the aspect of material fabrication.All of our attention has been directed toward the molecular pathway that leads to improve hydrogen evolution reactions performance.In addition,we have attempted to elucidate the spillover paths through the utilization of DFT calculations.Furthermore,we provide some preliminary research suggestions and highlight the opportunities and obstacles that are still to be confronted in this study area.

Operando NMR methods for studying electrocatalysis

The combination of electrochemical measurements with spectroscopic characterizations provides valuable insights into reaction mechanisms.Nuclear magnetic resonance(NMR)spectroscopy,as a powerful technique due to its atomic specificity and versatility in studying gas,liquid,and solid,allows the study of electrolyte solution,catalyst and catalyst-adsorbate interfaces.When applied in operando,NMR can offer molecular-level insights into various electrochemical processes.Operando NMR has been applied extensively in battery research,but relatively underexplored for electrocatalysis in the past two decades.In this mini review,we first introduce the operando electrochemical NMR setups,categorized by different probe designs.Then we review the applications of operando NMR for monitoring the electrolyte solution and the catalyst-adsorbate interface.Considering the high environmental impact of electrochemical conversion of CO_(2)into value-added products,we zoom in to the use of operando NMR in studying electrochemical CO_(2)reduction.Finally,we provide our perspective on further developing and applying operando NMR methods for understanding the complex reaction network of Cu-catalyzed electrochemical CO_(2)reduction.

Cerium-based nanomaterials for photo/electrocatalysis

The localization and incomplete filling of 4f electrons endow cerium(Ce)with the great potential in electrocatalysis and photocatalysis.The unique 5d empty orbital of Ce elements can be used as a hydrogen“trap”site,which is conducive to the recombination of hydrogen ions or atoms and effectively promotes the desorption of hydrogen molecules in electrocatalysis.Meanwhile,due to the stable crystal structure,excellent oxygen mobility,and good optical properties,Ce-based nanomaterials are considered as one of the most desirable photocatalytic catalysts and widely used in atmospheric conditions.Therefore,cerium-based nanomaterials have considerable application prospects in photocatalysis and electrocatalysis.In this review,we summarize the preparation methods of Ce-based nanomaterials,and discuss the application of Ce-based nanomaterials in electrocatalysis and photocatalysis.Among them,electrocatalysis applications include the following:oxygen reduction reaction(ORR),hydrogen evolution reaction(HER),oxygen evolution reaction(OER),CO_(2) reduction reaction(CO_(2)RR),and other electrocatalysis,and photocatalysis applications include HER,CO_(2)RR,photodegradation,and other photocatalysis.Through the summary of present progress in the application of Ce-based nanomaterials in electrocatalytic and photocatalytic reaction,this review provides a reasonable prospect on the Ce-based nanomaterials in electrocatalysis and photocatalysis.

A p-n WO_(3)/SnSe_(2) Heterojunction for Efficient Photo-assisted Electrocatalysis of the Oxygen Evolution Reaction

Water splitting is important to the conversion and storage of renewable energy,but slow kinetics of the oxygen evolution reaction(OER)greatly limits its utility.Here,under visible light illumination,the p-n WO_(3)/SnSe_(2)(WS)heterojunction significantly activates OER catalysis of CoFe-layered double hydroxide(CF)/carbon nanotubes(CNTs).Specifically,the catalyst achieves an overpotential of 224 mV at 10 mA cm^(-2)and a small Tafel slope of 47 mV dec^(-1),superior to RuO_(2)and most previously reported transition metal-based OER catalysts.The p-n WS heterojunction shows strong light absorption to produce photogenerated carriers.The photogenerated holes are trapped by CF to suppresses the charge recombination and facilitate charge transfer,which accelerates OER kinetics and boost the activity for the OER.This work highlights the possibility of using heterojunctions to activate OER catalysis and advances the design of energy-efficient catalysts for water oxidation systems using solar energy.

Interactive Oxidation of Photocatalysis and Electrocatalysis for Degradation of Phenol in a Photoreactor

TiO2/C particles as photocatalyst were prepared by dipping TiO2 suspension solution with activated carbon and were applied in the photocatalytic-electrocatalytic degradation of phenol, the Ti/SnO2+Sb2O3/PbO2 electrode and oxygen diffusion electrode were used as anode and cathode respectively, and a 250 W ultraviolet lamp (365 nm) as side light source. The SEM results of TiO2/C and Ti/SnO2+Sb2O3/PbO2 anode indicated that the TiO2 on carbon particles was uniform and PbO2 film on the surface of anode was in cauliflower form, the XRD result of oxygen diffusion electrode showed that only crystalline graphite was found. The influential parameters of degradation process such as applied cell voltage (E), initial concentration of phenol (C0), amount of TiO2 catalyst and air flow rate (v) were discussed. Under the following experimental conditions of C0=50 mg/L, pH=6, E=2 V, TiO2 0.98 mg/mL, v=382.2 mL/min, and light intensity I=10.5 mW/cm2, phenol could be entirely degraded, and about 89% of total organic carbon (TOC) was removed after 3 h degradation.

基于Photo Sphere Viewer的轻量化可量测街景系统研究

随着新型基础测绘体系发展,测绘技术和装备不断升级,大量街景数据随着车载激光扫描工作一并被采集。针对该数据路线随机性大、密集程度高等特点,以及传统街景地图系统插件受限、扩展性不强、无法量测等局限,本文设计了基于Photo Sphere Viewer的轻量化可量测街景系统,在开源插件的基础上实现了对其组件的扩充、实现了行进方向、地图交互等系统功能的设计优化,进一步实现了基于深度图的街景地图量测功能。生产作业队伍对系统的使用结果表明,该系统可以辅助生产作业队伍进行属性采集、纹理更新、数据检查等多项工作,操作灵活便捷,且具有较强的可扩展性,便于基于生产需求进行改进调整,提高了生产效率,为新型基础测绘成果进一步深化应用提供了良好的借鉴作用。

照片治疗技术的引进与发展——评《照片治疗技术》(《Photo therapy Techniques》)

《照片治疗技术》的作者是加拿大心理学家朱迪·韦泽(Judy Weiser),被公认为照片治疗技术的世界权威。1982年,朱迪·韦泽在加拿大创立照片治疗中心,该中心是世界上相关艺术领域的网络基地和教学数据资源库。目前,《照片治疗技术》已经被翻译为意大利语、韩语和俄语出版发行,著作的部分章节被翻译为日语和德语发行。

A Novel Electrocatalysis Method for Organic Pollutants Degradation

A novel electrocatalysis, ferrous ion catalyzed anodic-cathodic electrocatalysis (FACEC), was developed for organic pollutants degradation, which could promote the degradation by achieving synergetic effects of both anodic oxidation and cathodic indirect oxidation. The degradation rate of model pollutants - phenol by FACEC could increase by nearly 30% comparing with that of anodic electrocatalysis, and the current efficiency could reach 67%.

Electrocatalysis of carbon anode in aluminium electrolysis

The anodic over voltage of the carbon anode in aluminumelectrolysis is of the order of 0.6 V at normal current densities.However, it can be reduced somewhat by doping the anode carbon withvarious inorganic compounds. A new apparatus was designed to improvethe precision of over voltage measurements. Anodes were doped withMgAl_2O_4 and AlF_3 both by impregnation of the coke and by addingpowder, and the measured over voltage was compared with that ofUndoped samples. For prebake type anodes baked at around 1150 deg. C,the anodic overvoltage was reduced by 40-60 mV, And for Soderbergtype anodes, baked at 950 deg. C, by 60-80 mV.

Synergetic Effects of UV/Fe^(3+) Combined with Electrocatalysis for p-Nitrophenol Degradation

Synergetic effects for p-nitrophenol degradation were observed in the combination of two-advanced oxidation processes, UV/Fe3+ and electrocatalysis. The enhancement of removal rate for p-nitrophenol and COD was around 123% and 278%, respectively. The possible contributions for the synergetic effects were the electrochemically regeneration of ferric ion and the role of the oxygen that formed on the anode.

A review of nanocarbons in energy electrocatalysis: Multifunctional substrates and highly active sites

Nanocarbons are of progressively increasing importance in energy electrocatalysis, including oxygen reduction, oxygen evolution, hydrogen evolution, COreduction, etc. Precious-metal-free or metal-free nanocarbon-based electrocatalysts have been revealed to potentially have effective activity and remarkable durability, which is promising to replace precious metals in some important energy technologies,such as fuel cells, metal–air batteries, and water splitting. In this review, rather than overviewing recent progress completely, we aim to give an in-depth digestion of present achievements, focusing on the different roles of nanocarbons and material design principles. The multifunctionalities of nanocarbon substrates(accelerating the electron and mass transport, regulating the incorporation of active components,manipulating electron structures, generating confinement effects, assembly into 3 D free-standing electrodes) and the intrinsic activity of nanocarbon catalysts(multi-heteroatom doping, hierarchical structure,topological defects) are discussed systematically, with perspectives on the further research in this rising research field. This review is inspiring for more insights and methodical research in mechanism understanding, material design, and device optimization, leading to a targeted and high-efficiency development of energy electrocatalysis.

High-temperature electrocatalysis and key materials in solid oxide electrolysis cells

Solid oxide electrolysis cells(SOECs)can convert electricity to chemicals with high efficiency at ~600-900℃,and have attracted widespread attention in renewable energy conversion and storage.SOECs operate in the inverse mode of solid oxide fuel cells(SOFCs)and therefore inherit most of the advantages of SOFC materials and energy conversion processes.However,the external bias that drives the electrochemical process will strongly change the chemical environments in both in the cathode and anode,therefore necessitating careful reconsideration of key materials and electrocatalysis processes.More importantly,SOECs provide a unique advantage of electrothermal catalysis,especially in converting stable low-carbon alkanes such as methane to ethylene with high selectivity.Here,we review the state-of-the-art of SOEC research progress in electrothermal catalysis and key materials and provide a future perspective.

In-situ doping-induced lattice strain of NiCoP/S nanocrystals for robust wide pH hydrogen evolution electrocatalysis and supercapacitor

Developing high-efficiency multifunctional nanomaterials is promising for wide p H hydrogen evolution reaction(HER) and energy storage but still challenging. Herein, a novel in-situ doping-induced lattice strain strategy of NiCoP/S nanocrystals(NCs) was proposed through using seed crystal conversion approach with NiCo_(2)S_(4) spinel as precursor. The small amount of S atoms in NiCoP/S NCs perturbed the local electronic structure, leading to the atomic position shift of the nearest neighbor in the protocell and the nanoscale lattice strain, which optimized the H* adsorption free energy and activated H_(2)O molecules, resulting the dramatically elevated HER performance within a wide p H range. Especially, the NiCoP/S NCs displayed better HER electrocatalytic activity than comical 20% Pt/C at high current density in 1 M KOH and natural seawater: it only needed 266 m V vs. reversible hydrogen electrode(RHE) and660 m V vs. RHE to arrive the current density of 350 m A cm^(-2) in 1 M KOH and natural seawater, indicating the application prospect for industrial high current. Besides, NiCoP/S NCs also displayed excellent supercapacitor performance: it showed high specific capacity of 2229.9 F g^(-1) at 1 A g^(-1) and energy density of87.49 Wh kg^(-1), when assembled into an all-solid-state flexible device, exceeding performance of most transition metal phosphides. This work provides new insights into the regulation in electronic structure and lattice strain for electrocatalytic and energy storage applications.