Ag nanoparticles decorated WO3/g-C3N4 2D/2D heterostructure with enhanced photocatalytic activity for organic pollutants degradation

A novel Ag nanoparticles (NPs) decorated WO3 nanoplates/g-C3N4 (CN) nanosheets 2D/2D heterostructure was successfully synthesized by a solvent evaporation and in situ calcination method. The as-prepared WO3/Ag/CN ternary composite exhibited remarkably enhanced photocatalytic activity towards rhodamine B (RhB) and tetracycline (TC) degradation compared with WO3, CN, Ag/WO3, Ag/CN and WO3/CN under visible light irradiation. The enhanced photocatalytic activity could be attributed to the efficient separation of photogenerated charge carriers, the strong redox ability and enhancement of visible-light absorption derived from the construction of Z-scheme 2D/2D heterostructure. Ag NPs not only possess the surface plasmon resonance (SPR) effect, but also act as an electron mediator in Z-scheme heterostructure. The UV-vis absorption spectra analysis indicated that the loading of Ag NPs can enhance the visible-light adsorption. And the decreased photoluminescence and the increased photocurrent demonstrated the high separation rate of photoinduced charge carriers owing to the successful heterojunction construction. Furthermore, the possible degradation pathways of RhB and TC were proposed according to HPLC-MS analysis. The results of radical trapping experiments indicated that O-center dot(2)- and (OH)-O-center dot were the primary active species during the photocatalytic degradation process.