Sm2O3/S-doped g-C3N4 nanocomposites with enhanced photocatalytic activities under visible light irradiation

Some Sm2O3/S-doped g-C3N4 (CNS) composites were synthesized with in situ method by simultaneous combining S doping in carbon nitride structure to produce CNS as well as hybridization of CNS with the Sm2O3 semiconductor. The photocatalytic activities of composite photocatalysts were investigated for the degradation of methylene blue (MB) as a model pollutant in aqueous solution under visible-light irradiation. The optimal Sm2O3 loading value was determined to be 8.9 wt% and its corresponding MB photodegradation rate was about 93% after 150 min light irradiation, which was indeed greater compared with those of the individual CNS and Sm2O3 samples. This enhanced photocatalytic performance was originated from characteristics of the hybrid formed between the Sm2O3 and CNS so that it improved the effective charge transfer through interfacial interactions between both components. In addition, the CNS synthesized by Sdoping exhibited a significant enhancement in the photocatalytic activity relative to that of the pure g-C3N4; this was mostly caused by the increase in its visible light harvesting ability and charge mobility. The possible mechanism for the photocatalytic degradation of MB was suggested and discussed in detail based on the findings acquired from radical/hole trapping experiments.

Keywords:

Photocatalyst , Hybrid nanocomposite , Visible light irradiation , Sulfur-doped carbon nitride , in situ synthesis