Boosting photocatalytic hydrogen generation and Photo-Destruction of Tetracycline by In-Situ oxygen vacancies ZnIn2S4

Abstract

In this study, ZnIn₂S₄ with oxygen vacancies was fabricated using NaBH₄-assisted hydrothermal method to enhance the photocatalytic activities. The generated ZIS and ZISVo-x samples exhibited microspherical nanosheet structure and it is proven that NaBH₄ could enhance the amount of oxygen vacancies in ZnIn₂S₄ as confirmed by XPS analysis. Upon solar light irradiation, ZISVo-5 sample performed a fast photodegradation of tetracycline (TC) within 10 min and simultaneously exhibited a hydrogen evolution amount of ∼ 12 mmol (AQE = 6.07 at 420 nm), which is 2.75 times higher than that of pristine ZnIn₂S₄ (4.4 mmol). The degraded products of TC were further identified using LC-MS. The excellent photocatalytic HER performance was attributed to the optimum amount of oxygen vacancies in ZISVo-5 sample and the reactive oxygen species of •OH, O₂^•-, and ¹O₂ as confirmed by ESR analysis under light irradiation played a vital role for the rapid degradation of TC by ZISVo-5.