Tuning the Reactivity of Al@TiO2 Antenna-Reactor Plasmonic Photocatalysts by Controlling Oxygen Vacancies.

Oxygen vacancies on a metal oxide surface enhance its catalytic activity. Here we investigate the controlled introduction of oxygen vacancies on core-shell Al@TiO2 antenna-reactor nanoparticle photocatalysts. Thermal annealing in an H2-reducing atmosphere creates more oxygen vacancies in the surface TiO2 layer of Al@TiO2 nanoparticles compared to the same process under inert (He) or oxidative (O2) ambients. The photocatalytic reactivity enhancement was evaluated by investigating two reactions: hole-mediated methanol decomposition and electron-mediated hydrogen dissociation. The ability to modify plasmonic nanoparticle photocatalyst reactivity in this simple and controllable manner demonstrates the potential of this approach to tailor and enhance the performance of plasmonic antenna-reactor photocatalysts.