Simultaneous Photocatalytic Oxygen Production and Hexavalent Chromium Reduction in Ag_(3)PO_(4)/C_(3)N_(4)S-scheme Heterojunction

摘要

The low separation/migration efficiency is a major obstacle that limits the practical application of semiconductor-photocatalysts. Constructing S-scheme heterojunction is an ideal strategy for providing high photocatalytic activity via accelerating charge separation. Herein, an AgPO/CNcomposite was synthesized by coupling AgPOparticle with CNhollow spheres in-situ via a precipitation method. The S-scheme hete-rojunction between AgPOand CNcould accelerate the charge separation and retain high photoredox ability, which synchronously realized high photocatalytic oxygen production and hexavalent chromium reduction. The optimized Ag3PO4/CNcomposite shows a high oxygen production rate up to 803.31 μmol·g·hand a high conversion(87.9%) of Cr(Ⅵ) to Cr(Ⅲ). In addition, CNhollow spheres affords higher reaction efficiency than that of CNtube, CNbulk and CNsheet, which indicates that the hollow sphere structure can provide more active sites and adsorption sites in the photocatalytic process. This work offers an effective way in developing a dual-function S-scheme heterojunction for clean energy production and environmental protection.