The band structure and photocatalytic mechanism of MoS_2-modified C_3N_4 photocatalysts with improved visible photocatalytic activity

摘要

A series of MoS2/g-C3N4 photocatalysts were prepared by modifying g-C3N4 with different concentration of MOS2 via a water exfoliation method. The crystal structure, morphology, band structure of heterojunction, behaviors of charge carries and the redox ability were characterized by XRD, HR-TEM, absorption spectra, XPS, PL, cyclic voltammetry curves and transient photocurrent spectra. It is revealed that the introduction of MoS2 on the surface of g-C3N4 nanosheets to form micro-heterojunction could enhance the visible response and separate photogenerated charge carriers effectively. Moreover, the ability of the photocatalyst for generating reactive oxygen species (ROS, such as O-2(-) and center dot OH) was also investigated. Therefore, MoS2/g-C3N4 samples exhibit better photocatalytic performance for the photodegradation of HCHO than g-C3N4 and MoS2 under visible irradiation.