Strategic integration of MoO2 onto Mn0.5Cd0.5S/Cu2O p-n junction: Rational design with efficient charge transfer for boosting photocatalytic hydrogen production

Abstract

The rational design of durable and nonprecious nanocomposite photocatalysts with efficient charge separation and abundant active sites is still a grand challenge for photocatalytic hydrogen production from water reduction. Herein, a novel ternary nanocomposite, MoO2 decorated Mn0.5Cd0.5S/Cu2O p-n heterojunction has been constructed via a facile two-step route employing the energy band engineering theory. Impressively, the optimized ternary Mn0.5Cd0.5S/Cu2O/MoO2 nanocomposite displays a robust photocatalytic H2-evolution rate of 733.24 μmol h−1 under simulated solar light irradiation, more 4.2 times higher than pure Mn0.5Cd0.5S. The results demonstrated that the p-n heterojunction formed between n-type Mn0.5Cd0.5S and p-type Cu2O could markedly promote the interfacial charge transfer/separation through the internal electric field, whereas the MoO2 cocatalyst with low overpotential could effectively collect photoinduced electrons and dramatically facilitate the H2-evolution kinetics. Moreover, both Cu2O and MoO2 could improve the light-harvesting ability of pristine Mn0.5Cd0.5S, further contributing to the boosted hydrogen generation activity.