LAUSR

Abstract The low photochemical activity and stability of sulphides photocatalysts still remain a big challenge for the practical application. In this work, a simple post-synthesis method is developed to partially remove zinc in the as-prepared Zn0.3Cd0.7S sample, in which the unique amphiprotic nature of zinc is utilized mainly. Compared with the untreated Zn0.3Cd0.7S sample (ZCS), the treated Zn0.3Cd0.7S sample (VZn-ZCS) by alkaline solution has a 4.8 times higher BET surface area and contains more zinc vacancies. Under visible light irradiation (λ ≥ 420 nm), the photochemical activity of VZn-ZCS is 1.8 times higher than that of ZCS for the degradation of MB. Moreover, compared with ZCS, VZn-ZCS shows an improved photostability after three cycles, which is mainly attributed to the decreased VB oxidation potential by zinc vacancies. It is found that the formed zinc vacancy (VZn) can not only change the band structure, but also suppresses charge recombination as the hole trap. This post-synthesis strategy is simple and low-cost, which could be extended to the other photocatalysts. This work would contribute to the practical application of sulphides photocatalysts.