Photoenzymatic coupled catalysis, integrating semiconductor photocatalysis and enzymatic catalysis, exhibits great potential for light-driven synthesis. To make photocatalyst and enzyme at play concertedly, nicotinamide-based cofactors have been widely used as electron carrier. However, these cofactors are easily oxidized into enzymatically inactive form by photo-generated holes. Herein, oxidation mechanism of NADH, one typical nicotinamide-based cofactor, by photo-generated holes was reported. With CdS, g-C₃N₄ and BiVO₄ as hole generators, NADH is oxidized into NAD⁺ or fragmented into ADP-ribose derivatives through multi-step electron transfer. Importantly, fragmentation reaction is inhibited with dopamine and neutral red to coordinate electron transfer between NADH and photo-generated holes.