Gold nanoparticle incorporation into nanoporous anatase TiO2 mesocrystal using a simple deposition–precipitation method for photocatalytic applications

Abstract

Spindle-shaped nanoporous anatase TiO₂ mesocrystals with exposed active {101} facets have been successfully prepared through a hydrothermal method with tetrabutyl titanate as the precursor. By a deposition–precipitation process, highly dispersed Au nanoparticles loaded on spindle-shaped mesoTiO₂ exposed {101} facets, denoted as Au_x/mesoTiO₂, were firstly fabricated to establish close Schottky junctions to improve the visible light activity and the stability of Au on the catalyst surface. The photodegradation of methylene blue (MB) over Au_x/mesoTiO₂ was systematically investigated. The exposed active {101} facets together with the loaded Au nanoparticles dramatically enhanced the visible light photocatalytic activity of TiO₂. The synergistic effect of the high intrinsic single-crystal-like nature of the anatase phase, the stability of gold and the strong interaction between Au and mesoTiO₂ result in extraordinary photocatalytic stability of the catalyst. The detailed e⁻ and h⁺ separation dynamics for the visible-light and UV-vis induced catalytic mechanisms were discussed.