One‐step fabrication and high photocatalytic activity of porous graphitic carbon nitride synthesised via direct polymerisation of dicyandiamide without templates

Abstract

Porous graphitic carbon nitride (g‐C 3 N 4 ) has been synthesised by means of one‐step calcinations of dicyandiamide for efficient photocatalysis under visible light irradiation (λ > 400 nm). Scanning electron microscopy images demonstrate that the as‐prepared photocatalyst calcined at 650°C is a porous structure. The UV–vis diffuse reflectance spectra show that the optical absorption for the porous g‐C 3 N 4 is more intensive than for common g‐C 3 N 4 calcined at 550°C. The enhanced generation of the photocurrent under visible light irradiation (λ > 400 nm) is observed by using the porous g‐C 3 N 4 . The results of the photocatalytic experiments under visible light irradiation reveal that the photocatalytic degradation of methylene blue using the porous g‐C 3 N 4 is higher than common g‐C 3 N 4 , showing the advantage of the structure for efficient photocatalysis. The presence of the calcinations temperature is presumed to play a key role in adjusting the textural properties.