Preparation of Ag3PO4 tetrapods anchored to nitrogen-doped carbon quantum dots for enhanced photocatalytic performance

Abstract

A feasible modification strategy is proposed to enhance interfacial charge transfer in semiconductor microcrystals exposed to high-reactive facets for photocatalytic application. The Ag₃PO₄ tetrapods exposed with highly reactive {110} facets were synthesized, and then nitrogen-doped carbon quantum dots (NCQDs) were anchored on the surface of the Ag₃PO₄ tetrapods, constructing the nano-sized S-scheme NCQDs/Ag₃PO₄ heterojunction to further promote the interfacial charge transfer. Such S-scheme charge transfer behavior not only increased the efficient spatial separation of photo-generated carriers but also retained the strong-reductive electrons in the conduction band of NCQDs, which could fully harness ˙O₂⁻ to photo-catalytically degrade pollutants. Furthermore, the modification of NCQDs improved the light-harvesting ability of the composite due to the up-conversion fluorescence characteristic of NCQDs. Therefore, NCQDs/Ag₃PO₄ composite photocatalyst displayed outstanding photocatalytic performance for the degradation of methylene blue, which was about 3.4 times higher than that of pure Ag₃PO₄, and also exhibited higher stability.