Photo-piezoelectric synergistic catalytic performance of ZnIn₂S₄/PbBi₂Nb₂O₉ composites

Photocatalytic technology is one of the most effective ways to degrade organic pollutants, but the light absorption range of common photocatalytic materials is limited, and the recombination speed of photogenerated electrons is relatively fast, which greatly limits the application of photocatalytic materials. It is particularly important to develop high-performance catalysts with both light and stress responses by introducing an electric field to reduce the recombination of photogenerated electrons and holes, and to accelerate carrier separation and migration. In this study, ZnIn₂S₄/PbBi₂Nb₂O₉ composites were synthesized by growing ZnIn₂S₄/PbBi₂Nb₂O₉ composites on the surface of sheet PbBi₂Nb₂O₉ by low-temperature solvothermal method, and the efficient light-piezoelectric synergistic catalytic degradation performance under visible light was realized. Under the synergistic effect of light and ultrasonic vibration, the degradation rate of tetracycline hydrochloride (TC) by 50%-ZnIn₂S₄/PbBi₂Nb₂O₉ was 94.96% within 120 min, and the degradation rate constant was 8.38 times that of ultrasonic vibration only and 1.76 times that of light only. Its high catalytic performance can be attributed to the fact that PbBi₂Nb₂O₉ is used as a piezoelectric material, and under the action of ultrasonic vibration, a built-in electric field is formed inside the material, which effectively improves the separation efficiency of photogenerated carriers. At the same time, the S-type heterojunction formed between PbBi₂Nb₂O₉ and ZnIn₂S₄ also promotes the transfer of photogenerated electron-hole pairs.