Multi-doped Brookite-Prevalent TiO2 Photocatalyst with Enhanced Activity in the Visible Light

Abstract

Enabling solar and/or visible light-driven photocatalysis is a crucial step to access innovative applications in environmental science and sustainable energy. Titanium dioxide is the most used photocatalyst because of its low cost and toxicity, however it is also limitedly active under visible light irradiation due to its wide band gap. Among its polymorphs, brookite holds promising optoelectronic properties for visible light photocatalysis, which have to the best of our knowledge been limit-edly exploited. Here, a C,S,N-doped brookite-based TiO2 has been prepared via a rapid one-pot sol–gel synthesis. Besides substantially extending the visible light absorption via band gap narrowing, its photocatalytic activity has been enhanced further by optimising valence and conductive band position and by minimising electron–hole recombination. These materi-als showed a 100% boost in visible light absorption along with nearly 50-times enhanced photocatalytic activity per specific surface area than standard TiO2 Degussa-P25, giving the best performance among the brookite-based photo-catalytically active materials and resulting among the TiO2 top-performers under visible light.