Reinforcing Cd-S bonds through morphology engineering for enhanced intrinsic photocatalytic stability of CdS

Effectively mitigating photocorrosion is paramount for achieving high-efficiency and sustainable hydrogen production through photocatalytic water splitting over CdS. In this work, we develop a morphology engineering strategy with adjustable Cd-S bond energy through a simple chemical bath deposition method to synthesize novel hollow hemispherical CdS (H-CdS). The morphologic structure CdS can be precisely controlled by adjusting the reaction temperature, time and pH. Compared with common morphologies of CdS, H-CdS, with its reinforced Cd-S bonding, exhibits not only improved photocatalytic hydrogen evolution activity (20.04 mmol/g/h) but also exceptional resistance to photocorrosion, resulting in outstanding cyclic stability even without the aid of cocatalysts or the introduction of other semiconductors. Comprehensive characterizations reveal that the photocorrosion resistance of H-CdS stems from the high Cd-S bond strength. Moreover, in-situ infrared spectroscopy confirms alterations in the properties and activities of the various CdS morphologies after photocatalytic reaction due to photocorrosion. We thoroughly describe the relationship among morphology, surface energy, bond energy and photocorrosion resistance. Our findings present a novel strategy for mitigating the photocorrosion of CdS and offer valuable insights for future research on CdS photocatalysts aimed at stable water splitting.