Synthesis of mesoporous polymeric carbon nitride exhibiting enhanced and durable visible light photocatalytic performance

A thiourea precursor was employed to synthesize mesoporous carbon nitride (C3N4) by a thermal polycondensation process with high surface area SiO2 and nanosphere SiO2 as two types of hard templates. The resultant mesoporous C3N4 samples have high surface areas (105-112 m(2)/g) and mesopores with narrow sizes distribution (9.3 nm). Photocatalytic performance was evaluated by removal of NO in air under visible light irradiation. The results showed that mesoporous C3N4 samples exhibited significantly improved photocatalytic activity in comparison with bulk C3N4, which also exceeded that of N-doped TiO2 and C-doped TiO2. The activity enhancement can be ascribed to the synergistic effects of large surface area and pore volume, enhanced light-harvesting ability, increased redox potential, and reduced recombination of charge carriers. In addition to the high activity, the mesoporous C3N4 samples also showed high photochemical stability. The mesoporous C3N4 photocatalysts with enhanced and durable activity could provide a new efficient material for environmental pollution control.