Solvothermal synthesis of Bi ₁₂ TiO ₂₀ /Bi ₄ Ti ₃ O ₁₂ heterostructure with highly efficient photodegradation of MO under UV irradiation

Abstract

The sillenite-structured bismuth titanate (Bi 12 TiO 20 ) is thought to be a viable photocatalyst for environmental remediation. However, the performance of Bi 12 TiO 20 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 Bi 12 TiO 20 with adequate photocatalysts to create heterojunctions. Here, a one-step solvothermal technique is used to synthesize Bi 12 TiO 20 /Bi 4 Ti 3 O 12 heterojunction (BTO). The electric field that exists between B 12 TiO 20 , Bi 4 Ti 3 O 12 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 Bi 2 O 3 (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.