Long-term catalytic durability in Z-scheme CdS@ 1T-WS2 heterojunction materials

[Display omitted] •Improved photocatalytic durability by suppressing photo-corrosion of CdS particle.•Stable CdS nanorod wrapped by ultrathin 1T-WS2 2D nanosheet.•Slower photoluminescence decay and higher photocurrent density in 2CdS@1WS2 particle.•High concentrated hydrogen does not decrease even in the 10th recycling experiment.•Z-scheme charge transfer in CdS@WS2 junction particle. This study aimed to improve the long-term durability of CdS catalysts by reducing the deterioration of catalytic activity caused by photocorrosion. An ultrathin 1T-WS2 2D nanosheet was introduced to enclose the CdS nanorods. The crystal defects in the wrapped CdS particles were reduced, and the WS2 sheet became thinner in the junction particle. The 2CdS@1WS2 junction particle exhibited the slowest decay time of the photoluminescence curve, and the photocurrent density increased by more than 3.5-fold in the junction particle than the single CdS particle. Eventually, the optimized 2CdS@1WS2 catalyst exhibited a high rate of H2 production of ≈3935 μmol g−1h−1 under simulated solar light irradiation with a quantum efficiency of 50%. Although the recycling experiment was repeated over 10 times using the 2CdS@1WS2 junction particle, the produced hydrogen amount did not decrease. This result is because CdS nanorods wrapped stably by the ultrathin WS2 nanosheets, which suppressed the photocorrosion of CdS, and furthermore, the 1T phase WS2 rapidly attracted photogenerated electrons from CdS, facilitating charge separation and inhibiting their recombination, thereby improving the catalyst activity. Finally, it was revealed that an effective Z-scheme charge transfer mechanism in the CdS@1T-WS2 junction particle follows during water splitting.