Template-free synthesis of a novel porous g-C3N4 with 3D hierarchical structure for enhanced photocatalytic H2 evolution

Porous graphitic carbon nitride (g-C3N4) with three-dimensional. (3D) hierarchical structure was fabricated via a template-free approach by using cyanuric acid as a polymerization inhibitor. The hierarchical porous structure has a remarkable effect on the surface properties and photocatalytic performance of g-C3N4 for photocatalytic H-2 production under visible light irradiation (lambda > 420 nm). The photocatalytic H-2-evolution rate over the hierarchical porous g-C3N4 is 68.5 mu mol/h, which is about 4.8 times higher than that of pristine g-C3N4. Characterization results show that the formation of the 3D hierarchical porous structure results in the enlarged specific surface area, enhanced redox potential, and decreased recombination of photoinduced charge carriers of g-C3N4, contributing to the enhanced photocatalytic activity. (C) 2013 Elsevier B.V. All rights reserved.