Photoelectrochemical (PEC) water splitting to value-added hydrogen peroxide (HO) production is more promising than the traditional O evolution. However, enabling efficient PEC HO generation is still challenging due to competitive two-/four-electron water oxidation pathways. In this work, ZnInS (ZIS) photoanodes were engineered by Se doping and colloidal quantum dots (QDs) modification to boost the PEC HO evolution efficiency. Morphology and elemental studies testify the successful Se doping in ZIS and the anchoring of QDs on ZIS-Se photoelectrodes. Photoinduced carrier kinetics investigation verifies the optimized band bending, suppressed charge recombination, and promoted charge transfer in as-prepared ZIS-Se and ZIS-Se/QDs photoanodes, exhibiting inhibited four-electron O evolution and facilitated two-electron HO production during PEC water oxidation, as evidenced by the density functional theory (DFT) calculations. Accordingly, the Se-doped and QDs-decorated ZIS photoelectrodes demonstrate a gradually less upward band bending and improved photo-excited hole transfer to the surface, delivering a maximum HO production rate of 1.32 μmol min cm with a Faraday efficiency of 86 % at 1.23 V versus reversible hydrogen electrode (RHE) under one sun illumination.

中文翻译：

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ZnIn2S4 上的协同硒掺杂和胶体量子点修饰可实现高效光电化学过氧化氢生产


光电化学（PEC）水分解生产增值过氧化氢（H2O）比传统的 O 分解更有前景。然而，由于竞争性的二/四电子水氧化途径，实现有效的 PEC H2O 生成仍然具有挑战性。在这项工作中，通过 Se 掺杂和胶体量子点 (QD) 修饰设计了 ZnInS (ZIS) 光阳极，以提高 PEC H2O 析出效率。形态学和元素研究证明了 ZIS 中 Se 的成功掺杂以及 ZIS-Se 光电极上 QD 的锚定。光诱导载流子动力学研究验证了所制备的 ZIS-Se 和 ZIS-Se/QDs 光阳极中优化的能带弯曲、抑制的电荷复合和促进的电荷转移，在 PEC 水中表现出抑制四电子 O 的演化并促进双电子 H2O 的产生氧化，由密度泛函理论 (DFT) 计算证明。因此，Se掺杂和QDs装饰的ZIS光电极表现出逐渐减少的向上能带弯曲和改善的光激发空穴转移到表面，提供1.32 μmol min cm的最大H2O生产率，法拉第效率在1.23时为86% V 与单太阳照射下的可逆氢电极 (RHE)。