Aerobic Conditions Enhance the Photocatalytic Stability of CdS/CdOx Quantum Dots

Photocatalytic H-2 production through water splitting represents an attractive route to generate a renewable fuel. These systems are typically limited to anaerobic conditions due to the inhibiting effects of O-2. Here, we report that sacrificial H-2 evolution with CdS quantum dots does not necessarily suffer from O-2 inhibition and can even be stabilised under aerobic conditions. The introduction of O-2 prevents a key inactivation pathway of CdS (over-accumulation of metallic Cd and particle agglomeration) and thereby affords particles with higher stability. These findings represent a possibility to exploit the O-2 reduction reaction to inhibit deactivation, rather than catalysis, offering a strategy to stabilise photocatalysts that suffer from similar degradation reactions.