Construction of Novel Z-Scheme g-C3N4/AgBr-Ag Composite for Efficient Photocatalytic Degradation of Organic Pollutants under Visible Light

As a green and sustainable technology to relieve environmental pollution issues, semiconductor photocatalysis attracted great attention. However, most single-component semiconductors suffer from high carrier recombination rate and low reaction efficiency. Here, we constructed a novel visible-light-driven Z-scheme g-C3N4/AgBr-Ag photocatalyst (noted as CN-AA-0.05) using a hydrothermal method with KBr as the bromine source. The CN-AA-0.05 photocatalyst shows an excellent photocatalytic degradation performance, and a rhodamine B (RhB) degradation ratio of 96.3% in 40 min, and 2-mercaptobenzothiazole (MBT) degradation ratio of 99.2% in 18 min are achieved. Mechanistic studies show that the remarkable performance of CN-AA-0.05 is not only attributed to the enhanced light absorption caused by the Ag SPR effect, but also the efficient charge transfer and separation with Ag nanoparticles as the bridge. Our work provides a reference for the design and construction of efficient visible-light-responsive Z-scheme photocatalysts, and an in-depth understanding into the mechanism of Z-scheme photocatalysts.