Synthesis of novel g-C3N4/CaTiO3/CQDs heterojunction photocatalyst with enhanced visible light photocatalytic performance

In this paper, a high-efficient visible light responsive g-C 3 N 4 /CaTiO 3 /CQDs Z-type heterojunction photocatalyst was successfully prepared by a two-step method for the photodegradation of organic pollutants in water. The combination of g-C 3 N 4 , CaTiO 3 and CQDs could produce synergistic effect, which facilitated the separation of carriers, thereby enhancing photocatalytic activity . The photocatalytic kinetic removal rate of g-C 3 N 4 /CaTiO 3 /CQDs for methylene blue could reach about 8 times of g-C 3 N 4 and 5.5 times higher than that of CaTiO 3 . The effects of co-existing ions, initial pH, water source, and humic acid on meloxicam degradation were examined. Repeatability experiments indicated that the composite had good reusability and stability with 81.1 % removal for meloxicam after four cycles. The main active substances of g-C 3 N 4 /CaTiO 3 /CQDs in free radical capture experiment was ⋅O 2 − . Possible degradation pathways of meloxicam were also analyzed. The results highlight the g-C 3 N 4 /CaTiO 3 /CQDs Z-type heterojunction is a desirable photocatalyst for removing organic pollutants in water.