Band Gap Tuning in Poly(triazine imide), a Nonmetallic Photocatalyst

We have used a combination of X-ray and electron energy-loss spectroscopies along with DFT calculations to investigate the electronic structure of PTI/LiCl, a graphitic carbon nitride-type material with LiCl intercalation shown to photocatalyze the water-splitting reaction. The material is shown to have a band gap that is tunable with LiCl loading, with a minimum gap of 2.2 eV when fully loaded. This suggests that PTI/LiCl may be further optimized through control of their LiCl loading and shows that graphitic carbon nitride-type materials can be chemically tuned to improve their photocatalytic activity.