原位电化学调控钨基材料内建电场提升光电催化性能

以WO3、WSe2等为代表的钨基难熔金属化合物有望被广泛应用于光电催化中，近年来人们虽然从优化材料晶体结构和组成、调节半导体/溶液界面等方面取得了诸多突破，但其光电转化效率仍受制于较弱的内建电场驱动力。本项目提出了结合光电催化与充电电池机理构建额外体相内建电场并提升光电催化性能的新思路。通过原位电化学调控（锂化）的方式，利用金属离子电池（如锂离子电池）原理，精确可控地嵌入金属离子来诱导钨基材料的晶格扭曲并产生偶极矩，实现在整体光电极上形成额外的体相内建电场，促进电荷高效地分离和传输，进而大幅提升整体光电转化效率。在此基础上，本项目还将结合原位同步辐射表征和理论计算，阐明光电极的宏观电场与光生电荷分离与传输以及光电催化效率的构效关系，为体相内建电场优化调控光电催化性能的理论研究奠定基础，实现构建高效的钨基难熔金属光电催化材料并提供新的思路和方向。

As the representative of tungsten-based compounds, WO3, WSe2 and etc, are promising photoelectrodes in photoelectrochemical (PEC) reaction. Although many achievements have been made in the micro-structure and the adjustment of the photoelectrode/electrolyte interface to enhance built-in electric field in refractory metal-based photoelectrodes, the PEC performance is still limited by insufficient driving force for charge separation and transfer (CST). Herein, this project proposes, for the first time, a rational approach to design built-in electric field in the bulk of a tungsten-based photoelectrode by combining PEC process and an in-situ electrochemical (lithiation) process in the metal-ion (such as lithium ion) batteries discharge process. The inserted lithium-ion induces the lattice distortion and dipole moment with built-in electric field in bulk, which greatly facilitates the CST with improved overall PEC performance. Moreover, this project will conduct in-situ characterization, such as in-situ synchrotron and simulation to clarify the relationship between the electric field of the photoelectrode in bulk and CST/PEC performance, which is seldom investigated. Benefiting from the in-situ electrochemical exploration and basic theoretical study, this project will pave new path and direction towards the construction of high-efficiency tungsten-based photoelectrodes.