快速空穴转移及多活性位析氧助催化剂提升光电催化水分解性能研究

在光电催化水分解体系中，光生载流子的界面迁移以及表面的水氧化反应动力学是决定太阳能-氢转化效率的重要因素。因此，如何通过合理构筑助催化剂/半导体体系，有效抑制光生载流子的界面复合，同时加快表面的水氧化反应动力学，对推动光电催化水分解技术的发展具有重要的科学意义。本项目拟以α-Fe2O3作为光阳极体系的主体材料，依次通过前驱体纳米层的表面包覆、析氧助催化剂原位的二次生长实现快速空穴转移及多活性位析氧助催化剂在Fe2O3纳米阵列表面的可控构筑。利用协同光照X射线光电子能谱、瞬态荧光光谱等技术深入探究析氧助催化剂与半导体材料表面的紧密结合对界面电荷迁移的影响及作用机制。通过密度泛函理论计算考察水氧化反应中间活性物种的组成及其反应能垒，合理调控析氧助催化剂的表面形态，揭示多活性位析氧助催化剂促进水氧化反应动力学的内在机理，从而为构建高效、稳定的光阳极光电催化水分解体系提供理论依据和技术指导。

In the photoelectriccatalytic water splitting system, the interface transfer of photogenerated carriers and the surface water oxidation reaction kinetics are the most important factors that determine the solar-hydrogen conversion efficiency. Therefore, effectively suppressing the interface recombination of photogenerated carriers and accelerating the surface water oxidation reaction kinetics by rationally constructing a cocatalyst/semiconductor system are very important for the further development of photoelectriccatalytic water splitting technology. To address these issues, the proposed research uses α-Fe2O3 as the main material of the photoanode system, focusing on the controlled construction of oxygen evolution cocatalyst with rapid hole transfer and multi-active sites on the surface of Fe2O3 nanoarray by the surface coating of precursor nanometer layer and the in-situ secondary growth of oxygen evolution cocatalyst. Furthermore, the effect of the compact combination between oxygen evolution promoter and semiconductor material on the interface charge transfer is explored by synchronous illumination X-ray photoelectron spectroscopy and transient fluorescence spectroscopy; investigating the composition of the intermediate active species in the water oxidation reaction process and the reaction energy barrier through theoretical calculations, then rationally regulating the surface morphology of oxygen evolution cocatalyst, revealing the mechanism of the enhanced surface water oxidation reaction kinetics though multi-active sites, and finally providing theoretical basis and technical support for the construction of efficient and stable photoelectrocatalytic water splitting system.