近日，西南石油大学陈鑫团队揭示了晶体取向依赖的电荷转移动力学和界面水结构促进光电催化水氧化成H₂O₂。相关论文于2025年5月6日发表在《结构化学》杂志上。

光电化学水氧化反应（PEC-WOR）作为生产H₂O₂的可持续途径具有吸引力，但由于光生电荷效率有限和热力学不利，光阳极的活性低、产物选择性差。研究组通过晶体取向工程，WO₃光阳极暴露（200）面实现了优异的WOR活性（在1.76 V_RHE下为15.4 mA cm^-2）和对H₂O₂的高选择性（约70%）。综合实验和理论研究发现，WO₃-（200）的高PEC-WOR活性归因于在体相和WO₃（200）面的界面上快速的光生电荷分离/转移，这降低了电荷转移电阻。这与PEC傅里叶变换红外光谱所证明的WO₃-（200）/电解质界面上独特的缺陷氢键网络相结合，促进了WOR产生的H⁺的向外转移，降低了PEC-WOR的整体反应势垒。 

PEC-WOR对H₂O₂的优异选择性归因于独特的缺陷氢键网络，该网络减轻了WO₃-（200）面上*OH的吸附，与4-电子途径相比，这特别降低了2-电子途径的能量势垒。这项工作解决了晶体取向工程对光电催化活性和选择性的重要作用，并通过了解光照下的水吸附行为揭示了潜在的PEC机制。所获得的知识有望扩展到其他光电化学反应。

附：英文原文

Title: Crystal orientation dependent charge transfer dynamics and interfacial water configuration boosting photoelectrocatalytic water oxidation to H2O2

Author: anonymous

Issue&Volume: 2025-05-06

Abstract: Photoelectrochemical water oxidation reaction (PEC-WOR) as a sustainable route to produce H2O2 is attractive but limited by low activity and poor product selectivity of photoanodes due to limited photogenerated charge efficiency and unfavorable thermodynamics. Herein, by crystal orientation engineering, the WO3 photoanode exposing (200) facets achieves both superior WOR activity (15.4 mA cm-2 at 1.76 VRHE) and high selectivity to H2O2 (～70%). Comprehensive experimental and theoretical investigations discover that the high PEC-WOR activity of WO3-(200) is attributed to the rapid photogenerated charge separation/transfer both in bulk and at interfaces of WO3 (200) facet, which reduces the charge transfer resistance. This, coupling with the unique defective hydrogen bonding network at the WO3-(200)/electrolyte interface evidenced by operando PEC Fourier transform infrared spectroscopy, facilitating the outward-transfer of the WOR-produced H+, lowers the overall reaction barrier for the PEC-WOR. The superior selectivity of PEC-WOR to H2O2 is ascribed to the unique defective hydrogen bonding network alleviated adsorption of *OH over the WO3-(200) facet, which specially lowers the energy barrier of the 2-electron pathway, as compared to the 4-electron pathway. This work addresses the significant role of crystal orientation engineering on photoelectrocatalytic activity and selectivity, and sheds lights on the underlying PEC mechanism by understanding the water adsorption behaviors under illumination. The knowledge gained is expected to be extended to other photoeletrochemical reactions.

DOI: 10.1016/j.cjsc.2025.100619

Source: https://cjsc.ac.cn/cms/issues/801