Surface Hydroxylated S/O Dual‐Vacancy S‐Scheme Hollow [In2S3‐x/In2O3‐x](OH)y Heterojunction for Photothermal‐promoted Low‐Temperature Methanol/Water Reforming into Hydrogen

To enable highly efficient in situ hydrogen release from methanol/water reforming at lower temperature, the integration of solar-energy offers a promising approach to activate methanol/water and substantially lower the activation energy of this reaction. Herein, we present a novel dual-vacancy defective hollow heterostructure derived from Metal-Organic Frameworks, featuring abundant surface hydroxyl groups and S/O vacancies, for photothermal-promoted methanol solution reforming into hydrogen. The [In₂S_3-x/In₂O_3-x](OH)_y exhibits exceptional photothermal H₂ evolution activity, achieving a production rate of 215.2 mmolg_cat ^-1h^-1, 16-fold higher than its thermocatalytic activity, with an apparent quantum efficiency of 66.8 % at 365 nm and solar-to-hydrogen efficiency (STH) of 1.1 % under AM 1.5G simulated solar illumination, and excellent durability over 82 h, cumulating 2.61×10³ mmolg_cat ^-1. The synergistic effects of dual-vacancies and the hollow heterostructure significantly enhance the photothermal effect, lowering the activation energy barrier for methanol/water, enabling H₂ production at temperatures even as 80 °C under non-alkaline conditions. Furthermore, the incorporated surface hydroxyl groups facilitate the generation of active surface hydroxyls from water, further driving activation and cleavage of C-H bonds in methanol, thereby markedly reducing the apparent reaction activation energy by 12.5 %. This work provides a new strategy for effective H₂ production from aqueous methanol reforming under mild conditions, holding great promise for energy-demanding industrial applications.