Construction of ternary hollow TiO2-ZnS@ZnO heterostructure with enhanced visible-light photoactivity

Abstract

Through a simple fiber template method, we combined the n-type TiO2 catalysts with n-type ZnS@ZnO heterojunction to synthesize a high-efficiency ternary hollow TiO2-ZnS@ZnO n-n heterojunction. Under these modified conditions, the composite catalysts could broaden the visible light absorption range of the pure TiO2, and both the hollow structure and heterojunction could inhibit the recombination ability of the photon-generated carriers. Optical and Electrochemical characterizations indicated that the photogenerated electrons and holes can be separated efficiently and the composites have visible light absorption. The experimental results show that, the removal efficiency of the optimal composites for photocatalytic degradation of Tetracycline Hydrochloride (TC) under visible light (λ ≥ 420 nm) was 86.67% due to the ·O2− free radicals of efficient production, it exhibited 5 times higher degradation rate towards Tetracycline Hydrochloride (TC) than pure TiO2. The composites with high photocatalytic activity could also effectively degrade Methylthionine Chloride (MB), Xylenol Orange (XO), Acid Red 18 and Rhodamine B (RhB) under the driving of visible light. This work provided a simple method to construct ternary heterojunction, and also provided a promising strategy to solve the environmental pollution problem in the future.