Synergistic design for enhancing solar-to-hydrogen conversion over a TiO2-based ternary hybrid

Abstract

Enhancing the visible light responsiveness and photoactivity of TiO₂ is of strategic significance and is one of the hottest research frontiers. Traditional papers focus on extending the universality of each method with a series of different mechanisms, but only a few studies have discovered the huge importance of the synergistic enhancement effect when two or more conventional strategies are combined for one TiO₂ nanoparticle. Herein, a ternary pizza-like BE–Au–TiO₂ hybrid is deliberately designed based on a conjugated polymer (a modified poly(benzothiadiazole) flake, B-BT-1,4-E, denoted as BE) acting as a photosensitizer, Au nanoparticles serving as a surface plasmon resonance (SPR) source, and TiO₂ for electron collection and as a H₂ production medium. The mechanisms of sensitization and SPR-enhancement can be combined together to overcome the drawbacks of insufficient electron separation and transfer, and significantly improve the internal electron transfer efficiency over each mono-mechanism. Finally, the visible light-driven H₂ production rate of the BE–Au–TiO₂ hybrid is ∼1.9 and ∼68 times faster than that of BE–TiO₂ and Au–TiO₂, respectively, and a high AQY of 7.8% at 420 nm is obtained. This work opens a new window leading to the design of highly efficient photocatalytic H₂ production performance.