Controllable-Photocorrosion Balance Endows ZnCdS Stable Photocatalytic Hydrogen Evolution

Metal sulfide (MS) photocatalysts are highly attracted for visible-light photocatalytic hydrogen evolution (PHE), yet the ubiquitous issue of photocorrosion significantly undermines their photostability, often viewed as a detrimental effect. In this study, the positive impact of controllable-photocorrosion is highlighted on enhancing the PHE activity of MS photocatalysts. Specifically, it establish a clear structure-activity relationship for ZnCdS solid solutions fabricated via a unique sulfur-rich butyldithiocarbamic acid solution process. During the PHE process, the sulfur-rich surface of ZnCdS not only efficiently scavenges excess photogenerated holes but also facilitates the accumulation of sulfur produced from the surface layer photocorrosion of CdS. Leveraging the robust Zn─S chemical bonds, the photocorrosion of the ZnCdS photocatalyst is effectively confined to the Zn-subsurface region after the fifth cycle in long-term photostability tests, thus substantially delaying the internal destruction of ZnCdS. Consequently, the PHE rate of ZnCdS reaches 30.12 mmol g⁻¹ h⁻¹ after a long-term photostability test, representing a 2.5-fold increase compared to the initial rate.