In situ synthesis of Ag nanoparticles decorated on Ag2NCN heterostructures for increased visible-light photocatalytic degradation.

There is still a great demand for visible-light-driven photocatalysts for the efficient degradation of organic pollutants. Silver cyanamide (Ag2NCN) was reduced by NaBH4 in this work to prepare an Ag/Ag2NCN heterostructure, yielding uniformly dispersed metallic Ag nanoparticles (Ag NPs) on the surface of Ag2NCN plates. The Ag-1/Ag2NCN composite exhibited markedly enhanced visible-light photocatalytic activity towards rhodamine B (Rhb), phenol, and tetracycline (TC), with a rate constant of degradation 6.6 times larger than that of pristine Ag2NCN for TC. Structural and optoelectronic characterization revealed that the surface plasmon resonance of Ag broadens light absorption, promotes photothermal conversion, and facilitates charge separation via a built-in electric field at the heterointerface. The trapping experiments proved that superoxide radicals and photo-generated holes are the dominant reactive species. The synergy between Ag and Ag2NCN provides a rational design strategy for advanced carbodiimide-based photocatalysts.