Fabrication and characterization of ZnTiO3/Zn2Ti3O8/ZnO ternary photocatalyst for synergetic removal of aqueous organic pollutants and Cr(VI) ions

Highly efficient photocatalysts have great development prospects in wastewater treatment, especially in the degradation of organic pollutants and reduction of inorganic heavy metal ions. Herein, a Z-scheme ZnTiO3/Zn2Ti3O8/ZnO ternary photocatalyst was prepared by the solvothermal-calcination method and the influence of the content of tetrabutyl titanate precursor and different reaction temperature on the crystal phase structures, photoelectrochemical properties and photocatalytic activities of the samples were investigated. Due to its unique Z-scheme structure and suitable band gap position, which is favorable for the efficient migration and separation of photo-generated electrons and holes and the improvement of photocatalytic redox reaction capability, the samples show excellent performance for the degradation of organic pollutants and reduction of heavy metal Cr(VI) ions. Based on a series of characterization analyses, a possible Z-scheme photocatalytic mechanism is proposed. This work provides a simple preparation method for fabrication of multivariate heterojunction photocatalyst for degradation of organic pollutants and removal of heavy metal ions.