Template-free synthesis of g-C3N4 microprisms for significant enhancement of photocatalytic H2 evolution under visible light

Graphitic carbon nitride (C3N4) hexagonal microprisms were synthesized via a self-assembly route using (NH4)(2)CO3 as a structure-directing reagent. It shows that the extraordinary hierarchical structure is favorable to improving the photocatalytic activity of C3N4 toward water splitting under visible light irradiation (lambda>420 nm). The photocatalytic H-2-evolution rate on the microprisms is 185 mu mol/h, 16.8 times higher than that over bulk C3N4. The enhanced photocatalytic performance of the as-prepared micro prisms mainly originates from the characteristic micro-nanostructure, possessing enlarged surface area for efficient charge separation. (C) 2016 Elsevier B.V. All rights reserved.