Synthesis of lamellar O-doped ZnIn2S4 on layered g-C3N4 for boosted charge transfer and photocatalytic performances

Element doping is an effective approach to modify the electronic structure of semiconductors and improve the photocatalytic activity. Herein, we designed a process for the oxygen doping of lamellar ZnIn2S4 (O-doped ZIS) nanosheets that were coated on layered g-C3N4 (CN) to form a g-C3N4/O-doped ZnIn2S4 (CN/O-doped ZIS) heterojunction to improve the charge separation efficiency, thereby boosting the photocatalytic performance of CN/O-doped ZIS. The optimized 20% CN/O-doped ZIS showed high photocatalytic performance (RhB, 97% in 20 min) under visible light, which is 19.6 and 2.5 times higher than that of CN and O-doped ZIS photocatalysts, respectively. In the investigations on the band structure, trapping experiments, and ESR tests, the photocatalytic mechanism of RhB degradation by the CN/O-doped ZIS composite was proposed. The photocatalytic performance was effectively promoted via oxygen doping and coupling with CN, which opens new insight into a highly efficient photocatalytic system.