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

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@1WS(2) 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@1WS(2) catalyst exhibited a high rate of H-2 production of approximate to 3935 mu mol g(-1) h(-1) under simulated solar light irradiation with a quantum efficiency of 50%. Although the recycling experiment was repeated over 10 times using the 2CdS@1WS(2) 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. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

This study aimed to improve the long-term durability of CdS catalysts by introducing ultrathin 1T-WS2 2D nanosheets to enclose CdS nanorods. The optimized catalyst exhibited high H-2 production rate under simulated solar light irradiation with improved quantum efficiency. The result revealed an effective Z-scheme charge transfer mechanism in the CdS@1T-WS2 junction particle during water splitting.