Amorphous Metallic RuS2‐Enabled Solar Heating for Enhanced Photothermal Catalytic Oxidation of Halide Perovskite

Abstract Solar‐driven photothermal catalysis is among the most promising routes for efficient solar energy utilization. However, conventional solar heaters of carbon materials and plasmonic metals generally suffer from either insufficient surface reactivity or narrow absorption spectra confined to the visible region, greatly limiting photothermal catalytic efficiency. Here, amorphous metallic RuS 2 (RuS 2 ‐A) is demonstrated to function as an excellent solar heater, outperforming its crystalline semiconductor counterparts. It dramatically enhances solar energy conversion efficiency of MAPbBr 3 halide perovskite for benzylic C( sp 3 )‐H bonds oxidation by a factor of 33‐fold. Experimental characterization and theoretical calculations reveal that the hybrid RuS 2 ‐A/MAPbBr 3 composite enables synergistic utilization of the solar spectrum, in which MAPbBr 3 primarily absorbs low‐wavelength UV–vis light to generate charge carriers, while RuS 2 ‐A efficiently converts long‐wavelength visible‐NIR light into thermal energy. Crucially, an Ohmic junction is formed between the photoactive MAPbBr 3 semiconductor and the RuS 2 ‐A solar heater, enabling swift electron transfer to RuS 2 ‐A, which also exhibits strong O 2 activation capability. Together with thermal effect, photoelectrons are accumulated, locally heated, and finally consumed at the active RuS 2 ‐A sites, thereby greatly boosting the efficiency of photothermal catalytic toluene oxidation.