Stable and Highly Active Single Atom Configurations for Photocatalytic H<sub>2</sub> Generation.

Wang, Yue; Denisov, Nikita; Qin, Shanshan; Gonçalves, Danielle Santos; Kim, Hyesung; Sarma, Bidyut Bikash; Schmuki, Patrik · Adv Mater · 2024

basic_science · Level V

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Abstract

The employment of single atoms (SAs), especially Pt SAs, as co-catalysts in photocatalytic H<sub>2</sub> generation has gained significant attention due to their exceptional efficiency. However, a major challenge in their application is the light-induced agglomeration of these SAs into less active nanosized particles under photocatalytic conditions. This study addresses the stability and reactivity of Pt SAs on TiO<sub>2</sub> surfaces by investigating various post-deposition annealing treatments in air, Ar, and Ar-H<sub>2</sub> environments at different temperatures. It is described that annealing in an Ar-H<sub>2</sub> atmosphere optimally stabilizes SA configurations, forming stable 2D rafts of assembled SAs ≈0.5-1 nm in diameter. These rafts not only resist light-induced agglomeration but also exhibit significantly enhanced H<sub>2</sub> production efficiency. The findings reveal a promising approach to maintaining the high reactivity of Pt SAs while overcoming the critical challenge of their stability under photocatalytic conditions.