铜族金属纳米粒子调控铁钴基水氧化催化剂，协同催化机制及应用于α-Fe2O3光阳极

Water oxidation with oxygen evolving is one of the most important reactions in water splitting and various air batteries. However, it is kinetically sluggish and is a bottleneck reaction for the whole process. Aiming to improving the water oxidation reaction, this project proposes to introduce copper-group metal nanoparticles with high electronegativity onto the surface of iron-cobalt based oxygen evolution catalyst. The coupling effect between copper-group metal nanoparticles and iron-cobalt based compounds, and the Plasmon effect of copper-group metal nanoparticles are helpful to refine the bonding action between active catalytic sites and the oxygen intermediates, and thus reduce the water oxidation over-potential, enhance the electrocatalytic performance of synthetic materials. The influence rule of copper-group metal nanoparticles and their Plasmon effect on the performance of the iron-cobalt based catalysts will be investigated. The relationship between the composition, size, microstructure and the catalytic performance, stability of the composite catalyst, as well as the involved modulation rule will be analyzed. With this investigation and the analyses, this study tries to elucidate the active catalytic sites of the composite catalyst, the mechanism of water oxidation with oxygen evolving, and the synergistic catalytic principle among the components; to find out the most appropriate component match; to exploit water oxidation catalysts with excellent catalytic performance and high stability, as well as their optimal synthetic process. On this basis, the prepared composite catalyst will be applied onto α-Fe2O3 photoanode to optimize its oxygen evolution kinetics performance. Thus, this study will provide scientific guidance for the design, preparation of water oxidation catalysts with high performance and various photoanodes.

水氧化析出氧气是分解水和各种空气电池的最重要反应之一，但其动力学能垒高，是整个过程的瓶颈反应。本课题以水氧化为目标反应，提出将具有高电负性的铜族金属纳米粒子引入到铁钴基水氧化析氧催化剂表面，利用铜族金属纳米粒子与铁钴基催化剂间的耦合作用及其Plasmon 效应精细优化活性位点与氧中间物的键合作用，降低水氧化过电势，提升合成材料的电催化性能。课题研究旨在通过探究铜族金属纳米粒子及其Plasmon 效应对铁钴基催化剂性能的影响规律，分析复合催化剂组分，尺寸，微结构与催化性能及稳定性的相互关系及调变规律；以阐明复合催化剂的催化活性位点，水氧化析氧机理和各组分协同催化机制；找出最合理的组分搭配；力争开发出催化性能优，稳定性高的水氧化催化剂及其最优合成工艺。在此基础上，将复合催化剂应用于α-Fe2O3 光阳极优化其析氧动力学行为。课题研究将为高性能水氧化析氧催化剂及各类光阳极的设计制备提供科学指导。

项目研究以发展新型高效非贵析氧催化剂为目标，基于FeCo基复合物，探索了FeCo基催化剂的设计制备（包括催化电极的简易制备），铜族金属组分对催化剂电催化性能的影响，探究了催化过程中催化剂表面物相及微结构衍化，催化作用机制，考察了催化剂在氧化铁光阳极上的应用。通过细致考察FeCo基氧化物/氢氧化物，硫化物，硒化物等催化剂的制备及性能，系统表征催化剂在催化过程中的变化，发现各催化剂在催化过程中均会衍化为羟基氧化物或掺杂的羟基氧化物，这些衍生而来的羟基氧化物常具有弱结晶性和多孔结构，显示了比直接制备的羟基氧化物较高的催化活性。探明了铜族金属组分包括铜族金属离子或纳米粒子能优化FeCo基催化剂活性位点进而显著增强其催化作用及机制。特别的，发现铜族金属纳米粒子的Plasmon效应能通过其“热空穴”优化催化位点电子结构，进而增强电催化析氧作用。基于电解液中金属离子浓度变化，催化剂表面的重构分析及理论计算，建议了FeCo基复合催化剂中，铁位点为主要的催化活性中心。将所优化的催化剂应用于氧化铁光阳极，显著增强了氧化铁光阳极的光电化学性能。项目研究为先进电催化剂的研发及应用奠定了基础。