Novel Pt/CdS Schottky Junction Catalysts for Efficient and Stable Photocatalytic NADH Regeneration Through Optimized Carrier Migration and Free Radical Generation

Photocatalytic cofactor regeneration often encounters the problem of insufficient stability of reduced nicotinamide adenine dinucleotide hydrogen (NADH) regeneration due to the influence of reactive oxygen species. Here, we obtained Pt-loaded CdS nanorods (CdS NRs) with a one-dimensional (1D) rod-like structure by simple hydrothermal and photo-deposition methods. The yield of NADH improved by 52.54% within 40 min. Superoxide radical (·O 2 − ) had been proven to be the main reactive species that leaded to unwanted oxidation after NADH regeneration. After loading Pt, the formation of Schottky junctions between Pt and CdS NRs promoted the separation and migration of photogenerated carriers, resulting in a tendency of ·O 2 − to shift toward hydroxyl radical (·OH). ·OH produces additional intermediates in the oxidation of NADH compared to ·O 2 − , which inhibits the unwanted oxidation of NADH. Meanwhile, the conduction band position of Pt/CdS shifted positively and the ability to reduce O 2 was weakened, thus the ·O 2 − in the system was reduced, which weakened the oxidation of NADH and significantly improved the stability of NADH regeneration. These studies provide a new reference for applying loaded metal catalysts to the stable regeneration of NADH. Graphical Abstract