Novel RuSe2/Black-TiO2 photocatalysts for boosted photocatalytic degradation of rhodamine B: Preparation, performance and mechanistic investigation

Abstract

The current photocatalytic efficiency is greatly limited owing to severe electron-hole (e--h+) pair recombination. Finding inexpensive and highly active cocatalysts is an efficacious tactics for improve photocatalytic capability. Noble metal cocatalysts could significantly improve the photocatalytic efficiency of semiconductors. However, precious metals are too expensive to be used on a large scale. Herein, a novel highly efficient crystalline RuSe2 cocatalyst is reported and loaded on Black-TiO2 to form RuSe2/Black-TiO2 heterostructure. As far as we know, RuSe2 has not been documented as a fast electron-based photocatalytic cocatalyst trapping for photocatalytic degradation. The degradation rate of rhodamine B (RhB) by 0.5% RuSe2/Black-TiO2 reaches up to 97.23% within 60 min, while that of pure Black-TiO2 is only 60.53%. Additionally, RuSe2/Black-TiO2 has the advantages of narrow band gap, more active sites and better conductivity compared with pure Black-TiO2. Capture experiments and EPR experiments show that superoxide radicals are the main active species in 0.5% RuSe2/Black-TiO2.