Titanium dioxide and cadmium sulfide co-sensitized graphitic carbon nitride nanosheets composite photocatalysts with superior performance in phenol degradation under visible-light irradiation.

In this work, TiO2-CdS-gCNNSs heterojunction photocatalysts were successfully synthesized. CdS was deposited on the surface of gCNNSs via electrostatic attraction; TiOC, TiOCO and TiON bonds were produced in TiO2-CdS-gCNNSs, strengthening the interaction between TiO2 and gCNNSs. The TiO2-CdS-gCNNSs photocatalyst showed excellent photocatalytic activity for phenol degradation under visible-light irradiation, which was higher than that of CdS-gCNNSs, CdS-TiO2 and TiO2-gCNNSs. The improved photocatalytic performance of TiO2-CdS-gCNNSs was ascribed to more adsorption sites, enhanced light harvesting ability and effective separation rate of electron-hole pairs. Furthermore, the results of photocatalytic mechanism indicated that h+ and O2- played a more significant role on the phenol degradation.