Enhanced photoelectrochemical and photocatalytic activity by Cu2O/SrTiO3 p–n heterojunction via a facile deposition–precipitation technique

Abstract

In our study, a new visible-light-driven photocatalyst Cu₂O/SrTiO₃ (C/S) heterojunction was firstly prepared by a simple, facile and effective deposition–precipitation technique. The particle size of the Cu₂O nanoparticle is only about 5 nm and the SrTiO₃ (STO) nanocube is about 50 nm when modified by Cu₂O nanoparticles. The samples are used as photocatalysts for photodegrading tetracycline (TC) under visible light irradiation. The 9-Cu₂O/SrTiO₃ (9-C/S) sample heterojunction shows the highest TC degradation ratio (77.65%), which is caused by the photogenerated electrons of the Cu₂O nanoparticles moving from the conduction band of Cu₂O to that of SrTiO₃, resulting in the separation of electrons and holes. This study not only shows a possibility for substituting noble metals with low-cost Cu₂O nanoparticles in photocatalytic degradation but also exhibits a facile deposition–precipitation technique for synthesizing narrow/wide band gap photocatalysts.