Abstract:

Using H_1.07Ti_1.73O₄（HTO） as Ti source，strontium hydroxide octahydrate Sr（OH）₂∙8H₂O as Sr source，and solid ammonium tungstate［（NH₄）₁₀H₂（W₂O₇）₆∙xH₂O］ as W source，the SrTiO₃-SrWO₄ complex with different proportions were prepared by one⁃step hydrothermal method at 180 ℃.X-ray diffraction（XRD），scanning electron microscopy（SEM），ultraviolet visible absorption spectroscopy（UV-Vis），X-ray photoelectron spectroscopy（XPS） and other testing methods were used to study the structure and surface morphology of different complexes.At the same time，xenon lamp was used as the light source to degrade 10 mg/L methylene blue（MB） solution，and the photocatalytic degradation performance of different composite samples was investigated.According to the experimental results，the SrTiO₃-SrWO₄ complexes with different proportions were synthesized by hydrothermal method.When the composite sample was STW-9，the degradation performance was the best，and the degradation rate constant was 0.055 min^-1.The degradation rate constants of SrTiO₃ and SrWO₄ were 0.017 min^-1，0.01 min^-1，respectively，which indicated that the Z-type heterojunction formed between them improved the carrier separation efficiency.At the same time，the degradation rate of composite STW-9 could still reach 82% after repeated use for 5 times.The catalytic effect of the reactive species was hydroxylradica（·OH）>photogenerated holes（h⁺）>superoxide radical（·O₂^-）>photogenerated electron（e^-）.The hydroxylradical（∙OH） was proved to be the main active species.SrTiO₃-SrWO₄ composite material had low energy consumption and could provide reference for the treatment of organic pollutants in the future.

Key words: hydrothermal method, heterojunction, SrTiO₃-SrWO₄, photocatalysis