Engineering carbon-defects on ultrathin g-C3N4 allows one-pot output and dramatically boosts photoredox catalytic activity

Carbon defects engineering ultrathin porous g-C3N4 nanosheets with outstanding structural property (191.4 m2 g−1, 0.61 cm3 g−1) were fabricated by a thermal-triggering in-situ gas-shocking method which allows one-pot output for scale-up production, and a greatly-improved photocatalytic activity for hydrogen production was achieved (10.14 mmol h−1 g−1) under visible light. [Display omitted] •Carbon defects functionalized ultrathin porous g-C3N4 nanosheets were fabricated by an thermal gas-shocking methods.•Moderate Amino moiety can be in-situ formed on the edge of the g-C3N4 nanosheets.•Charge separation efficiency and reduction potential of photo-excited electrons can be both enhanced greatly.•The optimal photocatalyst U1W1-CNS presents superior photocatalytic H2 evolution performance and degradation efficiency. Herein, carbon-defect engineering and 2-dimensional engineering are integrated into g-C3N4 at once, allowing one-pot output of ultrathin g-C3N4 photocatalyst by a thermal-triggering in-situ gas-shocking process using endogenous gas (CO2, H2O, and NH3) from urea solution. The optimal photocatalyst U1W1-CNS presents an ultrathin structure (2 nm thickness) with abundant carbon-defects in a porous state, thereby endowed with outstanding structural property (191.4 m2 g−1, 0.61 cm3 g−1). Meanwhile, benefited from the emergent carbon defects, the conduction band of U1W1-CNS can be shifted to a higher energy level, thus contributing to stronger reduction ability which was comprehensively confirmed by experimental evidence and DFT calculation, and the hydrophilicity of U1W1-CNS is further improved by more exposed edge amino moieties. As expected, U1W1-CNS affords 57 folders of hydrogen production (10.14 mmol h−1 g−1) efficiency, and greater degradation efficiency for different organic pollutants RhodamineB (k = 0.0311 min−1), tetracycline (k = 0.0135 min−1), norfloxacin (k = 0.0091 min−1), ciprofloxacin (k = 0.012 min−1), and levofloxacin (k = 0.0078 min−1).