Thermal reflux to synthesise C3N4 nanostructures with high yield and enhanced photocatalytic activity in hydrogen evolution

Abstract

Graphitic carbon nitride (g-C₃N₄) is an attractive photocatalyst and a thermal reflux method was used to significantly increase the yield of g-C₃N₄ nanostructures and enhance their photocatalytic activity for H₂ production. When raw material was placed in an inclined quartz tube with the bottom in the high temperature zone and the top in the low temperature zone, the vapor of the raw material was condensed from the top and refluxed to the bottom to then participate in the reaction again. This method can significantly improve the yield of g-C₃N₄ with an increase of 28.2%. When used as the photocatalyst in water splitting, these g-C₃N₄ nanostructures exhibit excellent activity with an H₂ production of 2102 μmol h⁻¹ g⁻¹ under visible irradiation, which is 43.2% higher than the sample prepared by a traditional thermal polymerization method. This method is also promising to use for the synthesis of similar two-dimensional nanostructures for effective H₂ production.