Solvothermal synthesis of Bi12TiO20/Bi4Ti3O12 heterostructure with highly efficient photodegradation of MO under UV irradiation

Abstract

The sillenite-structured bismuth titanate (Bi12TiO20) is thought to be a viable photocatalyst for environmental remediation. However, the performance of Bi12TiO20 as a photocatalyst is severely constrained by its limited range of light sensitivity and the rapid photoinduced electron-hole pair recombination. A practical and effective way to overcome these limitations is to combine Bi12TiO20 with adequate photocatalysts to create heterojunctions. Here, a one-step solvothermal technique is used to synthesize Bi12TiO20/Bi4Ti3O12 heterojunction (BTO). The electric field that exists between B12TiO20, Bi4Ti3O12 and the closed interfacial contacts had a synergistic effect on the constructed composites, which resulted in high charge transfer abilities. Therefore, the BTO heterojunction demonstrated increased photocatalytic efficacy in the presence of ultraviolet irradiation. The MO removal efficiency of optimal BTO was 97.15%, significantly higher than that of pure Bi2O3 (46.9%). Furthermore, the cycling experiment demonstrated that the BTO heterojunction is stable and reusable. The probable mechanism of photocatalytic MO oxidation over BTO heterojunction was studied by various scavengers. The •OH radicals and holes played essential roles in BTO system of photocatalytic oxidation process.