Universal single-atom-enhanced catalyst for photocatalytic hydrogen production from water and ammonia

Photocatalytic water splitting and ammonia decomposition are promising industrial approaches for sustainable dihydrogen production. However, the development of a universal photocatalyst capable of efficiently generating dihydrogen from both water and ammonia has remained an unmet challenge. Here, we report a universal Pt single-atom TiO 2 /ZnIn 2 S 4 heterostructure that integrates 2D chemistry with atomic-level design to enable bifunctional photocatalytic dihydrogen production. This catalyst delivers dihydrogen evolution rates of 108.76 mmol g −1 from water splitting and 12.44 mmol g −1 from aqueous ammonia decomposition after 24 h of continuous irradiation, competitive with state-of-the-art photocatalysts. The bifunctional performance of the catalyst originates from the synergistic interaction among its three components. Atomically dispersed Pt sites, anchored via Pt–S and Pt–O bonds on coordinatively unsaturated sulfur and oxygen sites of ZnIn 2 S 4 and TiO 2 , respectively, accelerate interfacial reaction kinetics. ZnIn 2 S 4 contributes by extending visible-light absorption and optimizing the binding of hydrogen intermediates, while the TiO 2 /ZnIn 2 S 4 heterojunction ensures efficient separation and migration of photogenerated charge carriers. This study provides a rational design strategy for single-atom-engineered heterostructures toward universal and efficient solar-driven dihydrogen production.