Improved photocatalytic H2 production assisted by aqueous glucose biomass by oxidized g-C3N4

Chemically modified g-C₃N₄ for the photocatalytic H₂ evolution from water was explored. Bulk g-C₃N₄ was treated in hot HNO₃ aqueous solution to obtain the oxidized material (o-g-C₃N₄), tested in water containing glucose as model water-soluble sacrificial biomass, using Pt as co-catalyst, under simulated solar light. The behaviour of o-g-C₃N₄ was studied in relation with catalyst amount, Pt loading, glucose concentration. Results showed that H₂ production is favoured by increasing glucose concentration up to 0.1 M and Pt loading up to 3 wt%, and it resulted strongly enhanced using small amount of o-g-C₃N₄ (0.25 g L^?1). o-g-C₃N₄ possesses superior photocatalytic activity (～26-fold higher) compared to pristine g-C₃N₄, with H₂ evolution further improved by ultrasound-assisted exfoliation and evolution rates up to ca. 1370 μmol h^?1 per gram of catalyst, with excellent reproducibility (RSD < 6%, n = 3). Significant production was observed also in river water and seawater, with results far better (up to ca. 2500 μmol g^?1 h^?1) compared to commercial AEROXIDE^® P25 TiO₂ under natural solar light.