No abstract

Cu2ZnSnS4 nanoparticle with an average diameter of approximately 31 nm has been successfully synthesized by a time effective microwave fabrication method. The crystal structure, surface morphology, and microstructure of the Cu2ZnSnS4 nanoparticle were characterized. Moreover, the visible light photocatalytic ability of the Cu2ZnSnS4 nanoparticle toward degradation of methylene blue (MB) was also studied. About 30% of MB was degraded after 240 min irradiation when employing Cu2ZnSnS4 nanoparticle as a photocatalyst. However, almost all MB was decomposed after 90 min irradiation when introducing a small amount of H2O2 as a co-photocatalyst. The enhancement of the photocatalytic performance was attributed to the synergetic effect between the Cu2ZnSnS4 nanoparticle and H2O2. The detailed photocatalytic degradation mechanism of MB by the Cu2ZnSnS4 was further proposed.

Hydrogen produced from water splitting is a renewable and clean energy source. Great efforts have been paid in searching for inexpensive and highly efficient photocatalysts. Here, significant enhancement of hydrogen production has been achieved by introducing ≈1 mol% of MoS2 to Cu2ZnSnS4 nanoparticles. The MoS2/Cu2ZnSnS4 nanoparticles showed a hydrogen evolution rate of ≈0.47 mmol g−1 h−1 in the presence of sacrificial agents, which is 7.8 times that of Cu2ZnSnS4 nanoparticles (0.06 mmol g−1 h−1). In addition, the MoS2/Cu2ZnSnS4 nanoparticles exhibited high stability, and only ≈3% of catalytic activity was lost after a long time irradiation (72 h). Microstructure investigation on the MoS2/Cu2ZnSnS4 nanoparticles reveals that the intimate contact between the nanostructured MoS2 and Cu2ZnSnS4 nanoparticles provides an effective one‐way expressway for photogenerated electrons transferring from the conduction band of Cu2ZnSnS4 to MoS2, thus boosting the lifetime of charge carriers, as well as reducing the recombination rate of electrons and holes.