摘要
太阳能驱动的光电化学转化制燃料是解决能源危机、助力我国“双碳”(碳达峰、碳中和)目标达成的重要途径.常见的光电化学转化制燃料包括光电催化分解水制氢、二氧化碳转化制碳氢燃料等.上述光电催化反应是一个典型的界面析气反应过程,可在界面位点生成多种气体燃料.反应界面析气过程从表面的气体成核开始,以两相流结束.需要指出,该过程涉及不同时间和空间尺度的匹配以及各子过程的相互作用,对界面光子、电子、分子、离子等多载能子的耦合传输与转化有关键影响.本文的目的是阐明析气反应界面气泡生长各过程之间的内在联系.首先,以光电催化分解水为例,分析光电极表面气泡动力学多尺度过程及其对界面能质传递和转化的作用机理;随后,详细讨论微观尺度界面气泡成核、介观尺度气泡生长、宏观尺度气液两相流这一系列界面气泡生长演化的多尺度过程,并分析每一个子过程之间的耦合作用及其对光传递、物质传递、物质转化的影响规律;最后,对光电化学反应中界面气泡多尺度作用的研究挑战和未来方向进行展望.
The increasingly serious problem of the energy crisis requires the efficient use of renewable energy,including solar energy,wind energy,tidal energy,and so on.Among them,solar energy is regarded as the most promising candidate for a sustainable future because it is clean,extensive,and inexhaustible.Among the various methods of solar energy utilization,the photochemical conversion of solar energy into fuels is regarded as a long-term strategy for obtaining clean energy,which not only overcomes the inherent shortcoming of the intermittence of solar energy but also ensures environmental sustainability for society.Because of these characteristics,this pathway plays an important role in achieving China’s emission peak and carbon neutrality goals.Solar-powered water splitting and CO2 reduction are the most common schemes for solar-to-fuel conversion.In these schemes,various gaseous fuels can be produced at the active sites of the photocatalyst.Since the photochemical reaction is an interfacial reaction,the generation of gaseous products leads to the evolution of gas bubbles on the active surface.This gas evolution starts with nucleation and growth at the surface and ends in a gas-liquid two-phase flow in the reactor.There are several sub-processes involved in this process including microscopic nucleation,growth,coalescence,departure,and macroscopic gas-liquid two-phase flow.These sub-processes interact with each other and can play a significant role in the system performance.The objective of this review is to clarify the interactions between the multiscale processes during the interfacial gas bubble evolution at the photocatalyst.First,the general description of a model photochemical gas-evolving reaction of water splitting is presented.Based on the transfer characteristics and the reaction dynamics,the photochemically gasevolving systems are divided into four gradients corresponding to different characteristic lengths and time scales,i.e.,the quantum,molecular,mesoscale,and continuum scales.The interconnectedness be
作者
冯浩
张莹
刘东
李强
Hao Feng;Ying Zhang;Dong Liu;Qiang Li(Key Laboratory of Thermal Control of Electronic Equipment of Ministry of Industry and Information Technology,School of Energy and Power Engineering,Nanjing University of Science&Technology,Nanjing 210094,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2023年第25期3275-3292,共18页
Chinese Science Bulletin
基金
国家自然科学基金(51888103,52006101)
江苏省自然科学基金(BK20200491)资助。
关键词
光电化学
析气反应
界面气泡
多尺度
流动传递
photoelectrochemistry
gas evolution reaction
interfacial gas bubble
multiscale
flow and transfer
