Plasmonic Au–TiO2 interactions for augmented photocatalytic hydrogen evolution

The overreliance on non-renewable energy sources like fossil fuels has led to severe energy crises and environmental pollution, hindering sustainable development. Harnessing solar energy for water splitting through semiconductor photocatalysts offers a promising solution. Titanium dioxide (TiO2), a benchmark photocatalyst, is favored for its cost-effectiveness, non-toxicity, and stability under ultraviolet light. However, its weak light absorption, limited range, and high carrier recombination rates pose challenges. Herein, we designed an Au nanoparticle modified TiO2 (Au/TiO2) using a two-step method involving initial stirring adsorption followed by calcination. This composite material exhibits a localized surface plasmon resonance property, demonstrating powerful light absorption capacity in both the visible and near infrared regions. Moreover, following the decoration of Au nanoparticles, in situ XPS reveal Au/TiO2 exhibits a metal-support interaction, thereby enhancing the separation and migration of photogenerated carriers and decreasing the recombination rate of photogenerated charges. Thus, Au/TiO2 shows a photocatalytic hydrogen evolution rate of 47.89 mmol g−1 h−1, which is 39.25 times higher than that (1.22 mmol g−1 h−1) of pristine TiO2 and among the top rankings of TiO2-based photocatalysts. This study provides a novel approach to developing a photocatalyst capable of absorbing a broad spectrum of solar energy.