Skeletal tailoring of two-dimensional π-conjugated polymer (g-C3N4) through sodium salt for solar-light driven photocatalysis

Structural modification of graphitic carbon nitride (g-C3N4) by addition of sodium salt has been investigated for solar light-driven photocatalysis. The results from optical study indicates that the incorporation of sodium ions decreases band gap energy along with upward shifts of conduction and valence band. However, no substantial increment in surface area was observed, but morphological and optical studies confirm that the structural deformation of g-C3N4 through sodium salt activates the n - pi* electronic transition, which can extend the absorbption range to the red region attributing towards a reduced charge recombination, narrow band gap, and high conduction band edge. Furthermore, the photocatalytic activity of sodium doped g-C3N4 (0.6Na-g-C3N4) was examined under solar light for different operational conditions in terms of phenol degradation of real tannery effluent, and it was found that under optimum experimental conditions, i.e., 5 h solar irradiance, pH 5, H2O2 concentration 800 mg/L with a flow rate of 4 L/h, 0.6 Na- g-C3N4 exhibits 84.22% reduction in phenol while for g-C3N4 only 63.53% was observed.