Photocatalytic production of chemicals and fuels with H₂ evolution has raised broad interest due to the carbon emission-free feature. In this context, selective and fast scission of methanol C–H bonds for coproduction of H₂ and ethylene glycol (EG) over metal–semiconductor composites remains to be achieved. Here, we demonstrate that indium nanoparticles (In NPs) with a low work function (<4.3 eV) increase the selectivity and activity of ZnIn₂S₄ for the scission of methanol C–H bonds. By accepting electrons from In NPs, ZnIn₂S₄ with enriched electrons tends to activate the C–H bond instead of the O–H bond. Besides, a relatively strong built-in field is formed between In NPs and the support, which facilitates photogenerated electron transfer to In NPs for H₂ evolution. Consequently, 84% selectivity of EG is obtained, and the apparent quantum yields (365 nm) of EG and H₂ reach 15.6 and 27.0%, respectively. This concept of methanol C–H bond scission boosted by low-work function metal is also proved by immobilizing In, Cd, and Bi to ZnS, resulting in up to 89% selectivity of EG.

中文翻译：

---

低功函数金属促进甲醇 C-H 键的选择性和快速断裂

由于无碳排放的特点，具有 H ₂演化的光催化生产化学品和燃料引起了广泛的兴趣。在这种情况下，选择性和快速切断甲醇 C-H 键以在金属-半导体复合材料上联产 H ₂和乙二醇 (EG) 仍有待实现。在这里，我们证明了具有低功函数 (<4.3 eV) 的铟纳米颗粒 (In NPs) 提高了 ZnIn ₂ S ₄对甲醇 C-H 键断裂的选择性和活性。通过接受来自 In NPs 的电子，ZnIn ₂ S ₄富集电子倾向于激活 C-H 键而不是 O-H 键。此外，In NPs和载体之间形成了一个相对较强的内建场，这有利于光生电子转移到In NPs上进行H ₂的演化。因此，EG的选择性为84%，EG和H ₂的表观量子产率（365 nm）分别达到15.6%和27.0%。通过将 In、Cd 和 Bi 固定在 ZnS 上也证明了这种由低功函数金属促进的甲醇 C-H 键断裂概念，导致 EG 的选择性高达 89%。