硫缺陷型In2S3光催化剂高效分解水制氢研究

缺陷工程被认为是提高光催化剂分解水制氢性能的关键策略之一，然而有关缺陷诱导半导体材料电子结构演变并增强光生载流子传输机制尚不明确。在本研究中，我们通过简单的一步水热合成法成功构建了富含S缺陷的In2S3半导体光催化剂（VS-In2S3），在模拟太阳光辐照下其光催化分解水产氢性能相比传统的In2S3（P-In2S3）提升了近一个数量级（达到221.18 μmol/g/h）。此外，利用自主研发的原位X射线光电子能谱（SI-XPS）结合相关密度泛函理论计算证实：S缺陷可诱导强还原性的低价态In（In(3-x)+）暴露，进而增强In位点对H2O的吸附和活化能力，因此，S缺陷型In2S3表现出显著增强的光催化析氢活性。此外，可视化观测到H2O分子在原位光照下脱质子转化为OH的分解水制氢过程。该研究为缺陷型光催化剂设计及光催化分解水反应机制和过程研究提供了一定的见解。

Sulfur-deficient In2S3 photocatalyst for high-efficiency hydrogen evolution via water splitting

Defect engineering is considered as one of the key strategies to enhance the performance of photocatalysts for water splitting hydrogen production. However, it is still unclear how defects induce changes in the electronic structure of semiconductor materials and enhance the photogenerated carrier transfer. In this study, we successfully synthesized In2S3 photocatalysts with abundant sulfur defects (VS-In2S3) by a simple one-step hydrothermal method. It exhibits a photocatalytic hydrogen production performance of 221.18 μmol/g/h, nearly one order magnitude higher than In2S3 (P-In2S3). Furthermore, employing self-developed in situ X-ray photoelectron spectroscopy (SI-XPS) combined with density functional theory (DFT) calculations confirmed that sulfur defects induce the exposure of highly reducible low-valence state In (In(3-x)+), thereby enhancing the adsorption and activation capability of In sites towards H2O. Consequently, sulfur-defective In2S3 exhibits significantly enhanced photocatalytic hydrogen evolution activity. Additionally, the proton reduction of H2O molecules to OH have been visualized during the water splitting hydrogen production process under illumination conditions. This work provides new insights into defect-engineered photocatalyst design and the mechanism of photocatalytic water splitting reaction processes.