Efficient and Stable Inverted Perovskite Solar Modules Enabled by Solid-Liquid Two-Step Film Formation

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.

Improving advantages and reducing risks in increasing cyclone height via an apex cone to grasp vortex end

For a cyclone, it is possible to improve separation efficiency and reduce pressure drop by increasing the cyclone height. However, an exceeded height increase could result in a dramatical drop in separation efficiency. In this study, experimental and computational fluid dynamics simulation results exhibit that the introduction of an apex cone at the dust outlet could avoid the risk of separation efficiency drop but lead to a continuous reducing of the pressure drop. Generally, the optimal cyclone height should be closely related to the natural vortex length. While, when the vortex end contracts into the separation space in the cyclone with an exceeded height, severe back-mixing of particles always occurs, which will result in the decrease of separation efficiency. Herein, it is found that when an apex cone is installed at the dust outlet, the vortex end can be grasped by the cone so as to weaken the back-mixing of particles.Meanwhile, the introduction of this apex cone can enhance the secondary separation to capture the back-mixed particles again so as to protect the efficiency. In addition, it is found that the enhanced secondary separation could come from either the stagnant current of axial velocity in the center or the improved tangential velocity of inner vortex whereas the forcibly extending the length of vortex to exceed its natural length will not significantly increase efficiency.

Clean coal technologies in Japan： A review

Coal is the primary fossil fuel most used in the world for the electricity generation, iron making, and cement/concrete and chemical production. However, utilization of coal also results in emissions of CO_2, SO_x, NO_x and other noxious compounds. The development of clean coal technology(CCT) is a main issue to maintain a clean environment. CCT in Japan is considered the highest level in the world. In this review, the developing CCTs in Japan including high efficiency combustion technologies, advanced gasification technologies, CO_2 recovery and utilization technologies, and flue gas cleaning technologies are introduced and discussed. It is expected to provide some new view-of-points for CCT development.

Removal of biomass tar by steam reforming over calcined scallop shell supported Cu catalysts

In this study, the main purpose is to develop low-cost catalysts with high activity and stability for high quality syngas production via steam reforming of biomass tar in biomass gasification process. The calcined waste scallop shell（CS） supported copper（Cu） catalysts are prepared for steam reforming of biomass tar. The prepared Cu supported on CS catalysts exhibit higher catalytic activity than those on commercial CaO and Al;O;. Characterization results indicate that Cu/CS has a strong interaction between Cu and CaO in CS support, resulting in the formation of calcium copper oxide phase which could stabilize Cu species and provide new active sites for the tar reforming. In addition, the strong basicity of CS support and other inorganic elements contained in CS support could enhance the activity of Cu/CS. The addition of a small amount of Co is found to be able to stabilize the catalytic activity of Cu/CS catalysts,making them reusable after regeneration without any loss of their activities.

Multi-fluid Eulerian simulation of binary particles mixing and gas–solids contacting in high solids-flux downer reactor equipped with a lateral particle feeding nozzle

The performance of binary particles mixing and gas-solids contacting,which is considered qualitatively to have a significant influence on the heat transfer in internal heated circulating fluidized beds,is carefully investigated by means of a numerical approach in the newly developed high solids-flux downer lignite pyrolyzer(φ0.1 m×6.5 m).Since binary particles are used in this system,a reasonably validated 3 D,transient,multi-fluid model,in which three heat transfer modes relating to the convection,conduction and radiation are considered,is adopted to simulate the flow behavior,temperature profiles as well as volatile contents.The simulation results showed that the solids stream impinges the left wall surface initially and turns towards the right wall in the further downward direction and then shrinks during this process resulting in that the solids concentrate a little more at the central region.In the further downward section of the downer,the particle flow disperses near the right wall and develops uniformly.Meanwhile,the coal phase is slowly heated in the downer and it is found that most of the heat absorbed by the coal is from the convection heat transfer mode.To explore the heat transfer mechanism more quantitatively,two indexes(mixing index and contacting index)are proposed,and it is found that the mixing index initially increased fast and later remained at a relatively flat state.For the contact index,it shows a trend with a first rising and then falling,finally rising continuously.Also,it is found that the convection heat transfer is closely correlated to the contacting status of gas-coal which indicates that the improving of the gas-coal contacting efficiency should be an effective way to strengthen the coal particle heating process.

Preparation of Sn-β-zeolite via immobilization of Sn/choline chloride complex for glucose-fructose isomerization reaction

Well dispersion of tin species in an isolated form is a quite challenge since tin salts are easily hydrolyzed into（hydr）oxides during aqueous stannation of β-zeolite.In this study,immobilization of tin species on high silica commercial β-zeolite by using SnCl_2/Choline chloride（ChCl） complex followed with calcination provided a convenient way to get well dispersed Sn in β-zeolite in the aqueous condition,which was observed based on electron microscopy images,UV visible spectra and X-ray diffraction pattern.The existence of ChCl facilitated tin species to incorporate into zeolite.（1-2）wt%of Sn loaded β-zeolites exhibited good catalytic activity and high selectivity for glucose-fructose isomerization reaction.

Electron promoted ZnO for catalytic synthesis of higher alcohols from syngas

Direct conversion of syngas from those non-petroleum carbon resources to higher alcohols are very attractive due to the process simplicity with low energy consumption.However,the reaction always suffers from low yield as well as low selectivity.Herein,effective increase of higher alcohols proportion in the product is realized by direct conversion of syngas over electronically-modulated ZnO semiconductor via Cu doping.It is considered that the lower Fermi level and narrower band gap of catalysts by embedding Cu^(2+)into ZnO lattice could facilitate donor reaction by boosting the process for the reactants to obtain electrons on the catalyst surface for the formation of CH_(x) species and carbon chain growth,in which the Cu doping on ZnO lattice play important role in the promotion of CO adsorption.As a result,4 mol%Cu doped ZnO exhibits a highest C_(2+) OH/ROH fraction of 48.1%.Selectivity of catalysts from straight chain alcohol is better than from branch chain alcohol,which is different from promoted Cu/ZnO based catalyst.However,over-doping of Cu(7 mol%)on ZnO results in the aggregation Cu species on ZnO surface,leading to a sharp decrease of higher alcohols proportion to 3.2%.The results shed light on the nature that a direct correlation between semiconductor Fermi level and synthesis of higher alcohols,and the semiconductor-based catalysts mainly accelerate the hydrogenation reactions by enhancing thermally excited electron transfer.

水平井在日本南海海槽海域甲烷水合物开采中的应用

由于日本南海海槽海域甲烷水合物储层条件较为复杂,在2013年和2017年利用垂直井进行的现场开采试验中,未达到经济开采的产气量。因此,本研究旨在将水平井应用于南海海槽海域甲烷水合物的开采。因储层中存在三个具有不同物理性质(即初始水合物饱和度、孔隙度和固有渗透率)的含水合物亚层,因此在多层地质模型的基础上,设计了一些可能的井身结构,包括单水平井模式和双水平井模式,模拟真实的南海海槽海域甲烷水合物储层。然后,通过简单降压对海域甲烷水合物开采的长期模拟,验证了这两种井设计的有效性,并提出了每种设计的最佳井身结构。此外,在双水平井模式的基础上,采用降压和热水注入联合的方法进行了试验,其敏感性分析表明即使在相对较低的40℃注入温度和相对较小的2 kg/s/m的注入速度的情况下,第一年也能获得8.64×10^5m^3/d的有利产气量。

Electrodeposited iodide ions imprinted polypyrrole@bismuth oxyiodide film for an electrochemically switched renewable extractor towards iodide ions

Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched ion extraction(ESIE)process can be applied for effective capture and recovery of iodide ions(I^(-)).Herein,a novel kelp seaweed-like core/shell I^(-)imprinted polypyrrole@bismuth oxyiodide(PPy/I^(-)@BiOI)composite film is successfully prepared for the selective I^(-)capture in the ESIE system.It is found that the I^(-)can be easily trapped in the PPy/I^(-)@BiOI film after I^(-)is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^(-)extraction.The I^(-)imprinted PPy/I^(-)@BiOI film displays an extraction capacity as high as 325.2 mg·g^(-1)for I^(-)with favorable stability.In particular,the extraction and desorption of I^(-)is achieved by adjusting the redox potential and the pristine PPy/I^(-)@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity.It is expected that such a PPy/I^(-)@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^(-)from radioactive water.

Influence of Dry Methane Reactions on the Cell Output Characteristics of Solid Oxide Fuel Cells

In order to study the influence of dry methane concentration on outputs in solid oxide fuel cells (SOFCs), the output performance was obtained for dry methane of different concentrations on a Ni-ScSZ anode in solid oxide fuel cells, and the anode exhaust gas was measured by online chromatography. The underlying causes of the output performance change were analyzed from the anode reactions by summarizing the anode exhaust gas regular pattern for different reactions, and analyzing the electrochemical reaction kinetics of methane with oxygen ion. As the oxygen ion concentration at the anode three-phase boundary proportionally increased with current density, the following reactions occurred for different dry methane concentrations in sequence CH4 + O2﹣ → CO + 2H2 + 2e﹣, CH4 + 2O2﹣ → CO + H2O + H2 + 4e﹣, CH4 + 3O2﹣ → CO + 2H2O + 6e﹣, CH4 + 4O2﹣ → CO2 + 2H2O + 8e﹣. With various concentrations of methane at a low current, the outlet methane continuously reduced with the increase of the current density. Meanwhile, CO and H2 exhaust gas increased with increasing current density for low concentration of methane. With methane concentrations at 3.85% and 5.66%, the cell output voltage dropped rapidly. For concentrations of 29.7% and 3.85%, the anode exhaust residual methane changed irregularly with current density and this phenomenon was associated with the dry methane that reacted on anode of the cell. The transformation of reactions, the water produced in the electrochemical reactions and the polarization in response to the change of reactions maybe induced the output voltage and power density reducing as low concentrations of dry methane were used.

Simulation of gas-solids heat transfer in cyclone pyrolyzer using CFD-DEM model

Fast heat transfer in the pyrolyzer can increase the yield of pyrolysis gas and tar,and improve the quality of tar.Compared with the downer pyrolyzer,the cyclone pyrolyzer can simultaneously achieve high solids holdup and violent turbulence,and correspondingly faster heat transfer.In this work,the heat transfer behavior in the cyclone pyrolyzer is specifically studied using the computational fluid dynamics-discrete element method.The simulation results reveal that the gas-solids heat convection contributes mainly to the heat transfer process,and the heat radiation and conduction are relatively small and almost negligible,respectively.Compared with the downer pyrolyzer under the same operating conditions,the heating rate is significantly increased in the cyclone pyrolyzer.By analyzing the flow characteristics in the cyclone pyrolyzer,it is found that the region of high convective heat transfer rate coincides with that of natural cyclone length.Additionally,the final coal temperature increases with the increase of gas velocity and exists a maximum value.These results can offer some qualitative understanding of the heat transfer behavior in the cyclone pyrolyzer.

Metal organic frameworks-based cathode materials for advanced Li-S batteries: A comprehensive review

Li-S batteries(LSBs)have been considering as new and promising energy storage systems because of the high theoretical energy density and low price.Nevertheless,their practical application is inhibited by several factors,including poor electrical conductivity of electrode materials,greatly volumetric variation,as well as the polysulfide formation upon the cycling.To address these problems,it is imperative to develop and design effective and suitable sulfur host anode materials.Metal organic frameworks(MOFs)-based cathode materials,possessing their good conductivity and easy morphology design,have been extensively studied and exhibited enormously potential in LSBs.In this review,a comprehensive overview of MOFs-based sulfur host materials is provided,including their electrochemical reaction mechanisms,related evaluation parameters,and their performances used in LSBs in the past few years.In particular,the recent advances using in-situ characterization technologies for investigating the electrochemical reaction mechanism in LSBs are presented and highlighted.Additionally,the challenges and prospects associated with future research on MOF-related sulfur host materials are discussed.It is anticipated to offer the guidance for the identification of suitable MOFs-based sulfur cathode materials for high-performance LSBs,thereby contributing for the achievement of a sustainable and renewable society.

Fabrication of amorphous FeCoNiCuMnP x high-entropy phosphide/carbon composites with a heterostructured fusiform morphology for efficient oxygen evolution reaction

Amorphous high-entropy materials with abundant defects,coordinatively unsaturated sites,and loosely bonded atoms could exhibit excellent electrocatalytic performance.However,how to fabricate such ma-terials with nanostructure as well as amorphous structure is still full of challenges.In this work,high-entropy metal organic framework(HE-MOF)is employed as the self-sacrificial template to fabricate FeCoNiCuMnP x high-entropy phosphide/carbon(HEP/C)composites.The obtained composite shows a het-erostructured fusiform morphology,in which the HEP is encapsulated by a carbon layer,revealing high electron conductivity as well as rich catalytic active sites for oxygen evolution reaction(OER).Beside,it is found that there is a short-range ordered crystal structure in the amorphous phase,which is bene-ficial for revealing high OER catalytic activity as well as good stability.As a result,the optimum HEP/C composite shows an overpotential 239 mV@10 mA cm^(−2)with a small Tafel slope of 72.5 mV dec^(−1) for catalyzing OER in alkaline solution.

The swirl and pyrolysis reaction synergistically enhance solid-solid heat transfer and product separation in cyclone pyrolyzer Author links open overlay panel

Cyclone pyrolyzer is a novel type of downer that combines centrifugal force field and double-layer cyclone vortex.Research on transfer behavior is helpful to optimize the pyrolyzer to meet the needs of pyrolysis.In this study,the Computational Particle Fluid Dynamics(CPFD)model is used to analyze the transfer behavior of binary particles,and finds that the swirl and reaction have a synergistic effect.This effect can increase the heating rate of the particles to the range of flash pyrolysis,and its mechanism lies in the flow field structure of the pyrolyzer.Due to the centrifugal force field,the particles gather to the near wall.The rapid swirl,which facilitates intense gas-solid heat transfer,leads to the rapid heating and pyrolysis of biomass particles.As the pyrolysis proceeds,the mass of the biomass particles becomes smaller and they are more easily affected by the gas flow in pyrolyzer.Under the action of gas flow,char particles serve as new heat carrier to form the inner cycle of particles,which strengthens the heating process.The pyrolysis products are discharged from the exhaust port in time with the flow field of the pyrolyzer to achieve separation from the heat carrier and inhibit the occurrence of secondary reactions.

Photocatalytic degradation of tetracycline by copper(I)oxide loaded on Daylily Stalk derived carbon material

In this work,Daylily Stalks derived N doped carbon material(N-DSC)with a high specific surface area was firstly prepared by a chemical activation method,and then cubic Cu_(2)O nanoparticles were combined with the prepared N-DSC to obtain N-DSC/Cu_(2)O composite as the catalyst for the photocatalytic degradation of tetracycline(TC)antibiotics under visible light.It is found that the obtained composite had higher photocatalytic activity than pure Cu_(2)O.Particularly,25 wt%N-DSC/Cu_(2)O composite showed the highest photocatalytic performance with 95%of TC degradation within 100 min and more excellent stability.Combined with various characterizations,it is confirmed that carbon bonds should be conducive to the separation of photoelectron and hole,and the carbon layer with an excellent electrical conductivity on Cu_(2)O can reduce the charge transfer resistance between N-DSC and Cu_(2)O,thereby improving the absorption of visible light and enhancing the photocatalytic activity.Moreover,it is considered that the synergistic effect of photo-generated electron pair in Cu_(2)O and N-DSC could promote the photodegradation efficiency of N-DSC/Cu_(2)O composite.In addition,the active species capture experiment confirmed that·OH and·O_(2)should be the main active species for TC degradation under visible light.This study is expected to provide a novel low-cost photocatalysts for pollutants removal.

High entropy materials based electrocatalysts for water splitting:Synthesis strategies,catalytic mechanisms,and prospects

Among various electrocatalysts,high entropy materials(HEMs)have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability.To date,HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis.In this work,the structural features and synthesis strategies of high entropy catalysts are reviewed,especially,their performances for catalyzing hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)in water electrolysis are presented,in which the crucial roles of structure,composition,multisites synergy,and“four core effects”for enhancing catalytic activity,stability,and resistance of electrochemical corrosion are introduced.Besides,the design tactics,main challenges,and future prospects of HEM-based electrocatalysts for HER and OER are discussed.It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.

Electrocatalytic seawater splitting for hydrogen production:Recent progress and future prospects

Earth-abundant seawater resource has become an attractive candidate to produce hydrogen from electrolysis,which is of great significance to realize hydrogen economy and carbon neutrality.Nonetheless,developing highly active and stable electrocatalysts to meet the needs of highly effective seawater splitting is still challenging for the sluggish oxygen evolution dynamics and the existed competitive reaction of chlorine evolution reaction(CER).To this end,some newly-developed electrocatalysts with superior performance,such as noble metals,alloy,transition metals,oxides,carbides,nitrides,phosphides,and so on,have been synthesized for the seawater splitting in recent years.This review starts from the historical background and fundamental mechanisms,and summarizes the most recent progress in the development of seawater electrolysis technologies.Some existing issues in the process of seawater electrolysis are enumerated and the corresponded solutions are presented.The future of hydrogen production from seawater electrolysis,especially the design and synthesis of novel catalysts for seawater electrolysis,is prospected.

Recent progress in transition-metal-oxide-based electrocatalysts for the oxygen evolution reaction in natural seawater splitting: A critical review

Direct electrolytic splitting of seawater for the production of H2 using ocean energy is a promising technology that can help achieve carbon neutrality.However,owing to the high concentrations of chlorine ions in seawater,the chlorine evolution reaction always competes with the oxygen evolution reaction(OER)at the anode,and chloride corrosion occurs on both the anode and cathode.Thus,effective electrocatalysts with high selectivity toward the OER and excellent resistance to chloride corrosion should be developed.In this critical review,we focus on the prospects of state-of-the-art metal-oxide electrocatalysts,including noble metal oxides,non-noble metal oxides and their compounds,and spinel-and perovskite-type oxides,for seawater splitting.We elucidate their chemical properties,excellent OER selectivity,outstanding anti-chlorine-corrosion performance,and reaction mechanisms.In particular,we review metal oxides that operate at high current densities,near industrial application levels,based on special catalyst design strategies.

Application of ionic liquids in CO_(2)capture and electrochemical reduction:A review

As a new type of green solvent with non-volatility,high thermal stability,high conductivity and various adjustable properties,ionic liquid(IL)has been widely used in the capture and electrochemical reduction of carbon dioxide(CO_(2)).To date,many studies have been made to investigate CO_(2)capture by using different types of ILs and CO_(2)electrochemical reduction(CO_(2)ER)with ILs as either electrolyte or other catalytic active components.Some structure-activity relationships between the structure and adsorption or catalytic properties of ILs have been found.Herein,the absorption performances and mechanisms of conventional ILs,amino-functionalized ILs,non-amino functionalized ILs and supported ILs for CO_(2)capture,as well as the performances and action mechanisms of ILs as the electrolyte,electrolyte additive,and/or electrode modifier in the process of CO_(2)ER are summarized.Many researches indicate that the unique interaction between the anion or cation of IL and CO_(2)has a significant contribution to promote the absorption and conversion of CO_(2).However,the ILs used for CO_(2)capture and electrochemical reduction should be further explored.Especially,a more in-depth investigation of the adsorption and catalytic mechanisms with the help of quantum chemical calculation,molecular simulation,and in situ characterization techniques is necessary.It is expected to design and develop more efficient ILs used for CO_(2)capture and conversion on a large scale.

Interface engineering of Fe-Co_(3)N/CoP composite with N-doped C by using soybean:Fabrication of efficient electrocatalysts for oxygen evolution reaction

Soybean can serve as an efficient carbon and nitrogen source for in-situ fabrication of efficient composite electrocatalysts with conductive nitrogen-doped carbon(N-C)material.In this study,the iron-doped cobalt nitride/phosphide(Fe-Co_(3)N/CoP)nanosheet was composited with a conductive N-C material by using soybean as C and N source,as well as NH3 as additional nitrogen source.During the nitridation process of Fe-Co_(3)N,N-C bond was formed as a newly generated Co(Fe)-N-C active sites.Therefore,it fabricates a good microscopic contact interface between the catalyst and carbon material for charge transfer.Besides,the introduction of Fe-CoP by partially phosphating Fe-Co_(3)N further improved the OER activity due to the high catalytic activity of Co sites with high valence state.As a result,the obtained electrocatalyst exhibited overpotentials as low as 285 and 390 mV for supporting 10 and 100 mA/cm􀀀2 current densities.This work indicates that the design of materials with good interfaces could be an effective approach for the preparation of electrocatalysts for water electrolysis.