Molecule-induced gradient electronic potential distribution on a polymeric photocatalyst surface and improved photocatalytic performance

A polymeric photocatalyst was synthesized by coupling p-nitrobenzoic acid (PNA) onto graphitic carbon nitride (g-C3N4). The as-synthesized polymeric photocatalyst (PNA-g-C3N4) has a higher performance in the photodegradation of methyl orange (MO) than does g-C3N4. UV results show that PNA-g-C3N4 can harvest more solar energy than g-C3N4. Fluorescence results indicate that the separation efficiency of photo-induced electrons and holes in PNA-g-C3N4 is higher than that in g-C3N4. According to the experimental results and theoretical calculations, coupling PNA with g-C3N4 can narrow the band gap and introduce a gradient in the electronic potential distribution on the polymeric photocatalyst surface. The former results in the polymeric photocatalyst harvesting more solar energy, while the latter will favor the separation of photo-induced electrons and holes.