Fabrication and characterization of ZnGaTe/g-CN heterojunction with enhanced photocatalytic activity.

The extensive consumption of fossil fuels increases CO concentration in the atmosphere, resulting in serious global warming problems. Meanwhile, the problem of water contamination by organic substances is another significant global challenge. We have successfully synthesized ZnGaTe/g-CN (ZGT/GCN) composites for the first time as effective photocatalysts for both pollutant degradation and CO reduction. ZGT/GCN composites were synthesized by a simple hydrothermal method. The prepared photocatalysts were characterized by XRD, SEM, TEM-EDS, DRS, BET, PL, and XPS. The ZGT/GCN heterojunction exhibited considerably enhanced photocatalytic activity in the degradation of crystal violet (CV) as well as in the photoreduction of CO when compared to pure ZGT and GCN semiconductors. The optimal rate constant for CV degradation was obtained with the ZGT-80%GCN composite (0.0442 h), which is higher than the constants obtained with individual ZGT and GCN by 7.75 and 1.63 times, respectively. Moreover, the CO reduction yields into CH by ZGT-80%GCN was 1.013 μmol/g in 72 h, which is 1.21 and 1.08 times larger than the yields obtained with ZGT and GCN. Scavenger and ESR tests were used to propose the photocatalytic mechanism of the ZGT/GCN composite as well as the active species in the CV degradation.