Facile construction of carbon doped carbon nitride tube with increased π-electron density for highly efficient hydrogen production

Carbon doping is a promising strategy to enhance the catalytic performance of carbon nitride. Herein, a microtube-shaped carbon doped carbon nitride photocatalyst with increased π-electron density is developed, which is successfully applied in water splitting under visible light irradiation. The special tubular texture and the effective π delocalization caused by carbon doping largely broaden the light absorption range, boost the separation and transfer of charge carriers. The hydrogen evolution rate of carbon doped carbon nitride is enhanced by 3.1 times than that of the pure carbon nitride. And the experimental calculations and density functional theory indicate that carbon doping plays a critical role in improving catalytic performance owing to the increased π-electron densities. The unique tubular texture provides the improved surface area and numerous active sites for carbon nitride, which benefits the adsorption of reactant molecules and improves structural stability. Meanwhile, carbon doping can control electron density, adjust the band structure to accelerate charge carrier transfer and separation rate, and finally enhance the H2 generation rate. This work sheds light on the development of carbon nitride-based photocatalysts with a high H2 generation rate.