Simple Method to Synthesize g-C3N4 Doped Sn to Reduce Bandgap Energy (Eg)

Graphitic carbon nitride (g-C3N4) has been highlighted in its unique electronic structure with a medium bandgap, high thermal and chemical stability in the ambient environment. It is promoted as a photocatalytic material. To enhance photocatalytic properties, Sn-modified g-C3N4 was synthesized from urea and Sn powder. Firstly, urea was fired at 450-650oC in the air to synthesize g-C3N4 powder. Then such g-C3N4 powder was mixed with Sn powder for 0.1, 0.3, and 0.5 mole ratio and fired at 550oC in ambient. To investigate the phase formation and light absorption, XRD and light absorption spectrophotometers were performed, respectively. The light absorption value was used to calculate band gap energy (Eg). It was found that the XRD results of synthesized g-C3N4 were on the broad peak to narrow peak in synthesized temperatures 450-650oC. The light absorption of synthesized powder at 550oC was higher than others. Thus, synthesized powder at 550oC was chosen to mix with Sn powder. It observed that E g of Sn-modified g-C3N4 decreased depending on the amount of Sn and synthesized temperatures.