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.

Pt/MoC的制备及其在电解水析氢反应中的催化性能

以钼酸铵和氯铂酸为原料,通过原位程序升温碳化过程,合成了Pt负载量不同的Pt/MoxCy（x∶y≤2）催化剂,并考察了其在电解水析氢反应（HER）中的催化性能。利用XRD、BET、SEM、TEM、XPS对催化剂的微观结构及物理化学性质进行了表征。结果表明,Pt的负载改变了碳化钼形成的拓扑结构,Pt负载后的样品更容易形成α-Mo2C相。Pt的负载量对碳化钼催化剂在HER反应中的催化性能具有显著影响,1.6Pt/MoC[n（Pt）∶n（Mo）=1.6∶98.4]催化剂表现出最优催化效果（过电势ηonset=108m V,塔菲尔斜率b=74m V/dec）及较低的阻抗（18.77？）,可以与商业Pt/C催化剂相媲美。

燃料浓度对可燃气云爆炸影响的实验研究与数值模拟

以0.02mm厚度的聚乙烯薄膜为约束物,进行了半径0.5m的半球形乙炔/空气气云爆炸实验。结果表明,在100mJ弱点火条件下,乙炔的爆炸界限(乙炔的质量分数)由1.5%～82.2%缩小到5.3%～17.8%,乙炔的最危险质量分数为13.3%。建立了描述可燃气云爆炸的数学模型,并采用SIMPLE算法对模型进行求解,得到了不同燃料质量分数的爆炸超压分布。计算结果与实验值相比较,最大相对偏差为10.11%。对甲烷/空气、乙烯/空气、乙炔/空气等气云爆炸威力进行了预测,当处于最危险质量分数时,大体积的3种气云爆炸均可造成建筑物的损坏,而随着质量分数偏离最危险质量分数,破坏能力随之降低。

蒸汽喷射器超音速喷射流场的数值分析

针对不同边界条件和结构尺寸的喷嘴流场,通过数值计算,探讨了热力参数和几何参数对流场特性的影响规律,分析了喷嘴内影响喷射器性能的激波产生的因素,并建立了喷射器喷嘴内超音速流动的数学模型和计算方法。

平板形障碍物对气云爆炸强度影响的实验研究

以乙炔 -空气为介质实验研究了平板形障碍物对可燃气云爆燃强度的影响 ,运用曲线拟合方法获得了弱点火条件下气云爆燃时平板形障碍物上的压力分布与气云初始半径、平板离开爆源中心的距离之间的关系式 ,为气云爆炸的缩放研究提供了基础 .讨论了平板形障碍物对气云爆燃强度的影响 .

常规流场下各向异性扩散层对质子交换膜燃料电池(PEMFC)性能影响

为了研究扩散层各向异性对电池性能的影响,以XD=Diy,j/Dix,j为各向异性的表征,建立了使用常规流场的质子交换膜燃料电池二维传质模型。考虑了阴阳极内物质的对流和扩散、水和质子在膜内传递以及催化层的电化学反应。利用有限差分法对控制方程进行离散,采用逐次超松驰法求解得到了阴阳极反应气体和水的浓度分布以及催化层电流密度、膜中水含量、膜中电势和电流密度的分布。分析结果表明:在1≤XD≤4时增大XD有利于提高电池性能,但随着XD增大其对电池性能的影响逐渐减小;并且XD对电池性能的影响主要体现在对阴极和膜性能的影响上,其对阳极性能的影响甚微。

有扰流片的矩形通道内空气流动和传热过程的数值模拟

以高温透平叶片尾部区内部冷却为应用背景 ,对带顺排、错排扰流片肋的通道内空气流动和传热过程进行了数值模拟。计算结果表明 ,在相同雷诺数下 ,错排扰流片的阻力系数比针肋和顺排绕流片的阻力因子均增大约 2 % ,而冷却能力分别增大约 5 0 %和 9% .

不同型式流场的PEMFC内部传质分析

对采用不同型式流场的PEMFC进行建模,并用控制容积法对控制方程进行离散,求解得到PEMFC内部各物理量的分布以及综合水拖带系数、质子交换膜平均电导率等。分析了采用交趾型流场和常规流场时PEMFC的内部传质以及阴极性能、电池性能和膜性能,结果认为采用交趾型流场时,PEMFC阴极性能高于采用常规流场的PEMFC阴极性能,但质子交换膜的平均电导率低于采用常规流场时。在没有液态水产生时常规流场PEMFC性能高于交趾型流场PEMFC。

液化石油气爆燃的数值模拟

液化石油气是一种成分复杂的混合物 ,这就大大增加了对其爆炸进行数值计算的难度。采用CFD(ComputationalFluidDynamics,计算流体力学 )方法 ,对石油气的混合成分进行了简化处理 ,进而对石油气爆炸进行了数值模拟 ,建立了描述液化石油气爆燃的理论模型 ,采用SIMPLE算法对模型进行了求解。计算的超压与实验值相比较 ,球形容器内最大偏差为 9.0 9% ,平均偏差为 4 .5 8% ;开敞空间情况下 ,最大偏差 9.0 2 % ,平均偏差3.92 %。还对工业上可能产生的液化石油气可燃气云爆燃威力进行了预测 ,当气云半径为 10 0m时 ,最大超压可达 4 8.4 32kPa。研究表明 ,大尺寸气云可以产生具有破坏力的超压。

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.

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.

Estimation of CO₂Storage Capacity in the Real Sub-Seabed Sediments by Gas Hydrate

Beyond conventional methods for CO2 capture and storage, a promising technology of sub-seabed CO2 storage in the form of gas hydrate has come into the limelight nowadays. In order to estimate CO2 storage capacity in the real sub-seabed sediments by gas hydrate, a large-scale geological model with the radius of 100 m and the thickness of 160 m was built in this study, and the processes of CO2 injection and CO2 hydrate formation in the sediments with two-phase flow were simulated numerically at three different injection rates of 10 ton/day, 50 ton/day, and 100 ton/day for an injection period of 150 days. Then, the evolutions of CO2 reaction, free CO2, and hydrate formation over time were analyzed quantitatively, and the spatial distributions of the physical properties in the sediments were presented to investigate the behaviors of CO2 hydrate formation in the sediments with two-phase flow. For CO2 storage capacity, a total amount of 15,000-ton CO2 can be stored safely in the sediments at the injection rate of 100 ton/day for 150 days, and a maximum amount of 36,500-ton CO2 could be stored in the sub-seabed sediments per year for a CO2 storage reservoir with the thickness of 100 m. For the practical scenario, an average value of 1 ton/day/m could be used to determine the actual injection rate based on the thickness of the real sub-seabed sediments.

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.

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.

Micro-flower-like MoS_(2)-modified Co_(9)S_(8)heterostructure as anode material for sodium-ion batteries with superior reversibility and rate capacity

Designing and fabricating of heterostructured materials with long-term cycling stability and high-rate capacity for the anode of sodium-ion batteries(SIBs)still remain a great challenge.Herein,micro-flower-like MoS_(2)-modified Co_(9)S_(8)(Co_(9)S_(8)/MoS_(2))with a three-dimensional(3D)heterostructure was first obtained via a simple solvothermal synthesis followed by a solid sulfidation treatment process.As a material for the anode of SIBs,the Co_(9)S_(8)/MoS_(2)-based electrode with an initial Co/Mo molar ratio of 1/1(denoted as CM55-S)exhibits the best sodium storage performance with a boosted capacity,superior reversibility(424.5 mAh g^(-1)@2 A g^(-1)at the 1600th cycle,401.1 mAh g^(-1)@5 A g^(-1)at the 800th cycle),and an excellent rate capacity(210.1 mAh g^(-1)@20 A g^(-1)).Density functional theory(DFT)calculations confirm that the Co_(9)S_(8)/MoS_(2)heterostructure has a lower energy barrier(0.30 eV)than the pure Co_(9)S_(8)(0.53 eV).It is expected that such a heterostructured material could be an attractive candidate as the material of the anode for SIBs.

Utilization of fruit waste for H_(2)-rich syngas production via steam co-gasification with brown coal

In this work,to efficiently utilize waste fruit and low-rank coal for the hydrogen(H_(2))-rich syngas production,steam co-gasification of banana peel(BP)and brown coal(BC)was studied in a fixed-bed reactor.The results showed that the gasification rate of BC was highly enhanced after mixing it with BP and the obvious synergistic effect was observed in all investigated three mixing weight ratios(i.e.,1:1,1:4,4:1),resulting in a higher carbon conversion as well as a H_(2)-rich gas production yield for the co-gasification.However,the extent of promotion by synergistic effect was affected by the reaction temperature,mixing ratio,and steam amount.It was found that the high potassium(K)species content in the BP provided the catalytic effect not only on water-gas shift reaction but also on tar reforming/cracking,thereby enhancing the gasification of BC.In addition,it is confirmed that steam should be an important factor to promote the synergistic effect and H_(2)-rich gas production.

Zeolite-based cracking catalysts for bio-oil upgrading:A critical review

Fast pyrolysis of biomass is an attractive way to produce bio-oil since it can convert most of biomass components directly into liquid fuel. However, the bio-oils obtained from such a fast pyrolysis process always have highly complex oxygenated compounds with high viscosity, serious corrosivity, and rather instability. Thus, before the raw bio-oils are used as fuel or chemical feedstock, they must be upgraded, especially deoxygenated. Cracking of bio-oils over porous solid catalysts such as zeolite-based catalysts at ambient pressure is considered one of effective ways for the bio-oil upgrading, especially in which hydrogen gas is not necessary. Herein, zeolite-based catalysts (mainly HZSM-5 based catalysts) for the upgrading of pyrolysis bio-oils are critically reviewed. The effects of porous structure, acidity and other parameters including biomass type, biomass/catalyst ratio and operation temperature on cracking activity, selectivity, stability and deactivation are summarized. While, the proposed mechanisms on the bio-oil upgrading over the zeolite-based catalysts and the possibility for the application of the developed catalysts in the industrial process are discussed. Furthermore, the main strategies including metal modification, construction of zeolites with a hierarchical structure and synthesis of special morphologies with hollow structure or core/shell structure and nanosheet structures for the improvement of deoxygenation property performance are introduced. It is expected to provide a guidance for the design and fabricate more excellent zeolite-based catalysts and their application for high-quality bio-oil production from fast biomass pyrolysis.

Effect of nano Al_(2)O_(3) addition on cycling performance of poly(ether block amide)based solid-state lithium metal batteries

A novel poly(ether block amide)(PEBA)based solid-state polymer electrolyte(SPE)was prepared using a casting method,in which 20wt%lithium(Li)bis-(trifluoromethanesulfonyl)imide(LiTFSI)and aluminum oxide(Al_(2)O_(3))nanoparticles were used as the Li salt and solid plasticizer,respectively.In the case of addition of 3wt%Al_(2)O_(3) nanoparticles,ion conductivity of the obtained PEBA 2533-20wt%LiTFSI-3wt%Al_(2)O_(3) SPE was 3.57×10^(−5) S cm^(−1) at 25°C.Furthermore,the Li symmetrical battery assembled with it showed excellent cycling stability(1000 h)at 0.1 mA cm^(−2).While,the assembled all-solid-state Li/PEBA 2533-20%LiTFSI-3wt%Al_(2)O_(3)/LiFePO 4(areal capacity:0.15 mAh cm^(−2))battery maintained 94.9%of the maximal capacity(133.9 mAh g^(−1@0.1) mA cm^(−2))at 60°C even after 650 cycles with a superior average coulombic efficiency(CE)of 99.84%.By using X-ray photoelectron spectroscope(XPS),self-aggregation layer(SAL)of polyamide 12(PA12)of PEBA 2533 was discovered,which should contribute to promoting the robustness of lithium fluoride(LiF)enriched solid-electrolyte interphase(SEI)layer.In addition,it is considered that the state of interface between SPE and cathode should be the cause of voltage polarization of the full cell.

Downer reactor simulation and its application on coal pyrolysis:A review

Pyrolysis technology has received increasing attention in recent years due to its great potential in the field of lowrank coal clean and efficient conversion.Since pyrolysis reaction is very fast and prone to overreaction,the downer-type reactor is considered as a pyrolyzer due to its unique plug flow reactor characteristics.However,the low solids holdup,which is not beneficial for the fast heat transfer,limits its industrial application.Thus,how to realize high-density operation is crucial to the successful application of the downer reactor.Herein,the definition and strategies of high-density operation in the downer were introduced at first.And then,considering the increasing influence of computational fluid dynamics(CFD)in the fluidization industry,the state-of-the-art progress in downer simulation was reviewed,in which the newly developed drag models for downers were carefully discussed and compared.Also,to help prediction of the pyrolysis behaviors,the widely used pyrolysis kinetic models were systematically summarized.Combined with the potential of the downer in the field of coal pyrolysis,the relevant research progress of hot-state simulation of the downer pyrolyzer were introduced and analyzed.Finally,the suggestions on how to carry out follow-up work were given.It is expected that this review could give a better understanding for designing and optimizing downer pyrolyzer.