Fast carrier separation induced by the metal-like O-doped MoS2/CoS cocatalyst for achieving photocatalytic and photothermal hydrogen production

Abstract

Full solar-spectrum-driven hydrogen (H2) production from water-splitting is highly desirable but remains a great challenge. A heterojunction composite photocatalyst with a full-spectrum absorption range of up to 1020 nm was constructed by introducing 2D/2D metallic oxygen-doped MoS2/CoS (O-MC) nanosheets onto 1D Zn0.1Cd0.9S nanorods (ZCS NR) for photocatalytic and photothermal H2 production. Consequently, the optimal ZMC1.5 heterojunction exhibited a significantly improved H2 production activity of 95.5 mmol g−1 h−1 under 420 nm monowavelength irradiation, which is 13.84 times higher than that of pristine ZCS NR. Even under 1020 nm monowavelength irradiation, the catalyst also shows an expressive H2 generation rate of 0.202 mmol g−1 h−1. Moreover, it gives an apparent quantum yield (AQY) of 39.5% at 420 nm. Femtosecond transient absorption spectroscopy (Fs-TAS) results reveal the multiple intraband and interband excited-charge transitions in the partially occupied band of O-MC and interfacial electron transfer between O-MC and ZCS NR result in the enhancement H2 evolution rate. This study highlights the extended light absorption and special partially occupied energy bands of metallic cocatalysts, which hold great potential for the design and synthesis of efficient full solar-spectrum (UV–vis-NIR light) responsive photocatalysts.