Enhanced photocatalytic activity by tailoring the interface in TiO2–ZrTiO4 heterostructure in TiO2–ZrTiO4–SiO2 ternary system

Abstract

Abstract To clarify the interfacial structural of TiO2–ZrTiO4 heterostructure and their function in improving the catalytic behavior, TiO2–ZrTiO4–SiO2 photocatalyst with mesoporous structure, a large surface area (188.54 m2g-1) and an appropriate band gap energy (3.06 eV) was synthesized by in-situ reaction between TiO2 and ZrO2 at 800 °C in TiO2–ZrO2–SiO2 ternary system. The concomitant effects of loading amount of TiO2 and calcination temperatures on the interfacial interaction, and the corresponding interfacial effects on the photodegradation performance of the catalyst were investigated. Results show that an optimal amount of TiO2 is crucial in affecting the degree of interfacial interactions. Photocatalytic activity is significantly enhanced with the strong interfacial interaction between TiO2 and ZrTiO4 by forming heterojunction. A higher amount of TiO2 and calcination temperature will lead to the decrease in BET value, increase in pore size and band gap value, as well as the coarsening and aggregation of particles which exhibit negative influence on the interfacial interaction between TiO2 and ZrTiO4. In the photodegradation process, the prepared catalyst with a appropriate TiO2 molar ratio (Ti:Zr:Si, 5:1:6) exhibited a RhB-adsorption of 60.7% in dark reaction, and a degradation rate of 95% after visible light irradiation for 60 min. In addition, the probable degradation mechanism for the improvement in the degradation efficiency was discussed in detail.