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

Abstract

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.