Efficient photocatalytic hydrogen production of ternary composite constituted by cubic CdS, MoS2 and activated carbon

Abstract

CdS is a promising photocatalyst and combining MoS2 with CdS can realize efficient photocatalytic hydrogen production. However, most of the previous researches about MoS2/CdS composites focus on hexagonal CdS. Studies on cubic CdS are still rare due to its unstability. Thus in this paper, a ternary composite CdS-MoS2/C (abbreviated as CdS-MC, M = MoS2, C = activated carbon) was synthesized by facile in-situ liquid phase precipitation of cubic CdS on MoS2/C. Based on a series of characterizations, its photocatalytic hydrogen production performance was studied. Under the irradiation of a LED lamp, a high H2 evolution activity of 879.6 μmol h−1 was achieved for the composite CdS-10%MC, which is 23.3 times that of pure CdS. In addition, its performance is much higher than that of the hexagonal CdS-MC sample (265.6 μmol/h) obtained by heat-treatment of CdS-MC at 400 °C for 1 h under N2 atmosphere. What’s more, the stability of CdS-MC was investigated and the possible reasons for its unstability were analyzed in detail. To improve the stability, a method of 4-mercaptobenzoic acid (4-MBA) modification was also managed. Finally, possible mechanism for the photocatalytic hydrogen production of CdS-MC was proposed.