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1.
Yujie Xiong 《中国科学:化学(英文版)》2022,65(1):5-6
Photoelectrochemical(PEC)technique represents a promising approach to chemical transformation by harvesting sustainable solar energy.Despite the wide applications of PEC systems such as environmental remediation and solar energy conversion,the reported PEC reactions are dominated by the radical-based processes that are initiated by the single electron transfer between photo-induced carriers and adsorbed species on photoelectrode surface[1,2].For instance,hydroxyl radicals are often involved in the PEC oxidation reactions.As well known,it is a grand challenge to control the formation and evolution rates of radicals,which inevitably leads to the unsatisfactory product selectivity of PEC reactions.Naturally,such a circumstance brings about a question to the research community whether a different mechanism can be established to sustain efficient and selective oxygenation.Recently,based on their previous findings on PEC water oxidation[3,4],Zhao and coworkers[5]reported that many substrates can be oxidized in an oxygen atom transfer(OAT)pathway,a non-radical two electron process,to oxygenated products byα-Fe2O3 photoanodes. 相似文献
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Non-noble bifunctional electrocatalysts with robust activity and stability toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are greatly significant but challenging for Zn-air batteries. Here, in situ confinement of FeNx active sites in high porosity carbon framework (FeNx/CMCC) derived from chelate of carboxymethylcellulose (CMC) and iron ions were synthesized. Particularly, construction of FeNx within porous carbon framework accelerates the electron transfer and the sufficient utilization of active centers, and then expedites the reaction kinetics of ORR and OER. As expected, the optimized FeNx/CMCC exhibits superior ORR activity with a larger half-wave potential of 0.869 V. The rechargeable Zn-air battery delivers a higher power density of 99.6 mW/cm2 and a special capacity of 781.9 mA h/gZn at 10 mA/cm2, together with excellent durability of over 335 h. Remarkably, the as-assembled solid-state battery exhibits a higher open circuit voltage (OCV) of 1.5 V, a special capacity of 709.7 mA h/gZn, as well as prolonged cycling stability (90 h). Moreover, the flexible solid-state battery displays negligible loss of electrochemical performance under various bending angles, illustrating its potential application in flexible electronic devices. 相似文献
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随着经济的飞速发展,社会对能源的需求日益扩大,对工业废水的无害化处理也提出了更高的要求。光催化燃料电池 (photocatalytic fuel cell, PFC) 在燃料电池中引入半导体光催化材料作为电极,实现了有机污染物高效降解和同步对外产电的双重功能,在废水无害化与资源化利用方面具有潜在的应用价值。半导体光催化电极是PFC系统高效运行的核心组件,增强其可见光响应和光生载流子分离是提高PFC性能的关键策略。反应器结构设计和运行参数优化也有利于改善PFC性能。本文从PFC基本原理和应用入手,综述了PFC在环境污染物资源化处理中的研究进展,并详细阐述了提高PFC的污染控制性能和产电效率的优化手段,为进一步设计高效稳定的PFC系统并实现其在水污染控制和清洁能源生产中的应用提供理论指导。 相似文献
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Zhang Yaohui Li Tianbin Feng Wenkai Xiong Zuqiang Zhang Guoqiang 《Journal of Thermal Analysis and Calorimetry》2020,139(1):47-56
Journal of Thermal Analysis and Calorimetry - In order to find out the rules of the effect of temperature on performances and hydration process of sulphoaluminate cement-based dual liquid grouting... 相似文献
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Huadong Yuan Prof. Jianwei Nai Dr. Yongjin Fang Gongxun Lu Prof. Xinyong Tao Prof. Xiong Wen Lou 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):15973-15977
The growth of Li dendrites hinders the practical application of lithium metal anodes (LMAs). In this work, a hollow nanostructure, based on hierarchical MoS2 coated hollow carbon particles preloaded with sulfur (C@MoS2/S), was designed to modify the LMA. The C@MoS2 hollow nanostructures serve as a good scaffold for repeated Li plating/stripping. More importantly, the encapsulated sulfur could gradually release lithium polysulfides during the Li plating/stripping, acting as an effective additive to promote the formation of a mosaic solid electrolyte interphase layer embedded with crystalline hybrid lithium-based components. These two factors together effectively suppress the growth of Li dendrites. The as-modified LMA shows a high Coulombic efficiency of 98 % over 500 cycles at the current density of 1 mA cm−2. When matched with a LiFePO4 cathode, the assembled full cell displays a highly improved cycle life of 300 cycles, implying the feasibility of the proposed LMA. 相似文献
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In the conventional scheme of generating strong mechanical squeezing by the joint effect between mechanical parametric amplification and sideband cooling, the resolved sideband condition is required so as to overcome the quantum backaction heating. In the unresolved sideband regime, to suppress the quantum backaction, a χ(2) nonlinear medium is introduced to the cavity. The result shows that the quantum backaction heating effect caused by unwanted counter-rotating term can be completely removed. Hence, the strong mechanical squeezing can be obtained even for the system far from the resolved-sideband regime. 相似文献
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针对我国氧碘化学激光器输出能量不断提高的情况下,主要限制光束质量的因素之一是出光过程中的光腔失调,提出了一种基于图像处理的光学谐振腔自准直研究方法。该研究方法利用氦氖穿腔光通过凹腔镜中心孔,并在凸腔镜后方放置工业相机,在屏幕上方形成一个干涉同心圆环。通过借助OpenCV库中二值化、霍夫圆检测等图像处理的方法,获得干涉同心圆环的圆心坐标,再通过以圆心为中心将图像分成上下左右四个部分,通过判断这四部分亮点像素的数量差值来预估干涉同心圆环的偏移状态,进而获得空腔条件下光学谐振腔发生变化的理论判据。实验结果表明,该方法可以获得相当精准的光学谐振腔失调判据,其失调判据选取左右亮点像素差值30000,上下亮点像素差值45000,为今后失调判据与步进电机自动调腔的结合做好充足的准备。 相似文献
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