Ag SPR-promoted 2D porous g-C_3N_4/Ag_2MoO_4 composites for enhanced photocatalytic performance towards methylene blue degradation

摘要

Rapid recombination of photogenerated carriers has always been an important factor limiting advanced photocatalyst design. In this work, two-dimensional (2D) composites were successfully synthesized. Besides, crystal structure, micromorphology, optical properties, electrochemical properties, along with the photocatalytic methylene blue (MB) performance and photostability have been systematically explored. Porous graphite carbon nitride (Pg-C3N4) was composited with Ag2MoO4 forming a large-scale heterojunction interfaces, which is not only beneficial to supply more reaction active sites for catalytic reaction, but reduce the distance during the photoexcited carriers transfer. In addition, Ag surface plasmon resonance (SPR) effect acts as a very important role in photodegradation process, which makes great contributions to boosting the separation of photoexcited electron-hole pairs. The Pg-C3N4/Ag2MoO4 composites exhibit an excellent photocatalytic MB degradation and photostability, which can degrade MB solution by 99.5% in 12 min. The k(app) of 40%Pg-C3N4/Ag2MoO4 is 0.33065 min(-1), which is much higher than that of Pg-C3N4 (0.01606 min(-1)) and Ag2MoO4 (0.00933 min(-1)). Moreover, trapping experiment was employed to determine the specific reactive species, indicating that hole plays a major role in MB photodegradation. This work provides an available method to conduct a 2D photocatalyst with large-scale heterojunction, which is a promising material for the application in photocatalytic water pollution treatment.