Homogeneous double-layer TiO2-ZrO2-SiO2 photocatalyst with multi-heterojunction structure for enhanced visible light-responsive photocatalytic activity

Traditional heterojunctions are usually constructed with different material systems, resulting in weaker interfacial effects in the catalytic system. In order to solve this problem, we use a simple sol-gel method to construct a homogeneous double-layer TiO2-ZrO2-SiO2 photocatalyst with multi-heterojunction (D- TZS), which can effectively improve the photocatalytic property. By investigating the influence of various factors on the photocatalytic performance, the degradation rate of Rh B by D-TZS can reach about 99.6 % within 40 min of photoreaction, and Rh B almost completely degraded within 60 min. This is attributed to three aspects of homogeneity, multiple heterojunctions and oxygen vacancies. Firstly, the inner and outer layers are homogeneous with excellent compatibility, and the outer layer has strong adsorption. Secondly, the multi-heterostructure which forms between the inner-layer multi-heterojunction and the outer layer can separate the photogenerated electrons in each layer to a certain extent. Finally, the oxygen vacancies formed after the bonding of the outer and inner layers can further enhance the mobility of photogenerated carriers. This idea provides new methods for the study of homogenous multiple heterojunctions with high visible light degradation rate. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

We constructed a homogeneous double-layer TiO2-ZrO2-SiO2 photocatalyst with multi-heterojunction (D-TZS) using a simple sol-gel method, which effectively improves the photocatalytic property. By investigating various factors, we found that D-TZS can degrade Rh B by about 99.6% within 40 minutes and almost completely degrade it within 60 minutes. This is attributed to the homogeneity, multiple heterojunctions, and oxygen vacancies of D-TZS.