Efficient Photocatalytic Hydrogen Production Coupled with Glycerol Valorization Driven by Fully Condensed Potassium Poly (Heptazine Imides)

Abstract Photocatalytic water splitting emerges as a transformative technology for sustainable hydrogen energy production. However, reliance on sacrificial hole scavengers (e.g., triethanolamine) in conventional systems leads to significant underutilization of oxidative potential and increases the cost of hydrogen production. Coupling photocatalytic hydrogen evolution with the oxidative valorization of biomass‐derived polyols establishes a dual‐functional system that simultaneously enhances solar energy conversion efficiency and creates economic value through the coproduction of high‐value‐added chemicals. In this study, the energy band structure and charge carrier behaviors of poly (heptazine imides) are modulated by salt‐melt polymerization in the presence of different gas flow atmospheres (e.g., NH ₃ , CO ₂ , N ₂ ). Accordingly, the optimum potassium poly (heptazine imide) synthesized in the presence of CO ₂ presents excellent performance for visible‐light photocatalytic hydrogen production (apparent quantum yield(AQY) = 44% under λ = 420 nm) coupled with glycerol valorization for selective synthesis of dihydroxyacetone (DHA, ∼ 146 µmol of DHA per hour). This study provides new insights into the rational design of carbon nitride photocatalysts, as well as the concurrent achievement of hydrogen evolution coupled with the production of high‐value‐added chemicals.