biostudies-literatureUnknown25(12)Bhoyar TSummary Regeneration of electron carriers such as NAD+/NADH is highly desirable and essential for enzymatic conversions. Here, we demonstrate a sustainable strategy for the regeneration of NAD+ as an electron carrier via photon-assisted heterogeneous catalysis. For this, a mid-gap state induced nitrogen-rich polymeric carbon nitride (NPCN) catalyst was synthesized by an additive-assisted thermal copolymerization. Utilizing NPCN as a photocatalyst presented NADH photooxidation efficiency of over 98% and a high hydrogen production rate of 11.18 mmolg−1h−1 with an apparent quantum yield of 9.16% (λ = 420 nm), outperforming other state-of-art metal-free photocatalysts. The experimental and theoretical simulations suggest that mid-gap states in NPCN catalyst are main platform for charge-carrier separation that enhances the overall photocatalytic performance. Graphical abstract Highlights • Additive assisted synthesis of N-rich PCN (NPCN) with mid-gap states is proposed• About 98% of NADH oxidation is realized using NPCN photocatalyst• A photocatalytic hydrogen evolution rate of 11.18 mmolg−1h−1 was achieved on NPCN• Existence of mid-gap electronic states facilitate charge carrier separation Catalysis; Materials chemistry; Materials science.iSciencehttps://www.ebi.ac.uk/biostudies/studies/S-EPMC9713345biostudies-literatureAccelerating NADH oxidation and hydrogen production with mid-gap states of nitrogen-rich carbon nitride photocatalystPMC9713345Kim DAbraham BGupta ATonda SUmare SBhoyar TVidyasagar DManwar NMaile NfalseAccelerating NADH oxidation and hydrogen production with mid-gap states of nitrogen-rich carbon nitride photocatalystSummary Regeneration of electron carriers such as NAD+/NADH is highly desirable and essential for enzymatic conversions. Here, we demonstrate a sustainable strategy for the regeneration of NAD+ as an electron carrier via photon-assisted heterogeneous catalysis. For this, a mid-gap state induced nitrogen-rich polymeric carbon nitride (NPCN) catalyst was synthesized by an additive-assisted thermal copolymerization. Utilizing NPCN as a photocatalyst presented NADH photooxidation efficiency of over 98% and a high hydrogen production rate of 11.18 mmolg−1h−1 with an apparent quantum yield of 9.16% (λ = 420 nm), outperforming other state-of-art metal-free photocatalysts. The experimental and theoretical simulations suggest that mid-gap states in NPCN catalyst are main platform for charge-carrier separation that enhances the overall photocatalytic performance. Graphical abstract Highlights • Additive assisted synthesis of N-rich PCN (NPCN) with mid-gap states is proposed• About 98% of NADH oxidation is realized using NPCN photocatalyst• A photocatalytic hydrogen evolution rate of 11.18 mmolg−1h−1 was achieved on NPCN• Existence of mid-gap electronic states facilitate charge carrier separation Catalysis; Materials chemistry; Materials science.2022-01-01T00:00:00Z2022 Nov2025-04-26T12:31:56.77Z2025-02-19T04:15:04.631ZS-EPMC9713345