Boosting Visible Light Photocatalysis in an Au@TiO2 Yolk-in-shell Nanohybrid

Abstract Yolk-shell nanohybrids have garnered increasing interests in many applications, such as in catalysis, energy, and molecular sensing. However, their intrinsic architectural limitations have led to insufficient synergistic effects and instability which are unfavorable for nanocatalysis. Designing a unique yolk-in-shell nanostructure where the “yolk” is embedded in the “shell” can overcome this challenge to boost nanocatalysis. Herein, an unprecedented Au@TiO2 yolk-in-shell nanocatalyst has been developed to dramatically improve the visible light photocatalysis. The as-designed Au@TiO2 nanohybrid displays an efficient hydrogen-production (95.6 mmol h-1 g-1, Au: 0.04 wt%), 3- and 14-times better than conventional Au@TiO2 yolk-shell nanostructure and pure TiO2 hollow nanosphere, respectively. Our unique design also notably achieves high selectivity (~100%) towards CO production (0.75 mmol h-1 g-1) under visible light irradiation. This unique yolk-in-shell nanoarchitecture promises enormous opportunities for the design of next-generation hybrid nanocatalysts with enhanced catalytic performances.