Strong coupling effects at the interfacial sites of a heterojunction formed by 0D/2D Ir quantum dots and TiO2 ultrathin nanosheets for robust photocatalytic H2 production

Abstract

In this study, we designed a novel two-dimensional ulrathin TiO₂ nanosheet structure decorated with Ir quantum dots via an immersion method for photocatalytic H₂ production. The resulting Ir-modified TiO₂ (Ir/TiO₂) possess excellent and stable photocatalytic H₂ production activity, with the H₂ production rate of 3% Ir/TiO₂ being 21 times that of pure TiO₂. This enhanced photocatalytic activity is attributed to the interface sites formed between the two-dimensional ultrathin structure and Ir quantum dots, which increase visible light absorption, accelerate the separation of photogenerated charges, and evidently lower the reaction barrier. Additionally, the unique two-dimensional nanosheet structure of TiO₂ provides a high surface area for optimal dispersion of Ir quantum dots. The size of Ir nanoparticles increased only slightly, from 1.1 nm to 2.1 nm, after five cycles, indicating high stability. This work presents a potential strategy for designing 0D/2D photocatalysts for efficient H₂ production.