Synthesis and characterization of TiO2/ZnO heterostructural composite for ultraviolet photocatalytic degrading DOM in landfill leachate.

Abstract

In order to investigate the photocatalytic degradation of dissolved organic matter (DOM) in landfill leachate, TiO2/ZnO heterostructural composite powders were fabricated combining with hydrothermal synthesis and solid-state reaction method. The prepared TiO2/ZnO composite powders consist of anatase TiO2 nanoparticles distributing on the surface of wurtzite ZnO particles. The optical band gap of TiO2/ZnO powder is less than that of pure ZnO or TiO2 powder. TiO2/ZnO catalyzers show high ultraviolet-degradation efficiency for methylene blue and dissolved organic matter. The degradation rate of TiO2/ZnO powder for fulvic acid-like substances in landfill leachate is 2.99 times that of pure ZnO powder, and is 1.30 times that of pure TiO2 powder. The degradation of fulvic acid-like substances by TiO2/ZnO photocatalyst reduced some molecular weight of benzene ring structure substances in leachate. The effective separation of electron and hole in heterostructural TiO2/ZnO photocatalyst is the main reason for its high photocatalytic degradation efficiency of DOM in landfill leachate.