Extended Visible Light Absorption Combined with Promoted Charge Carrier Transfer in Urea-Derived Graphitic Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution Performances

Graphitic carbon nitride (GCN) is a rising star in photocatalysis due to its chemical stability, economic suitability, and variable modulation of structures. However, the inefficient charge carrier transfer to reactants as well as the restricted visible light absorption greatly hinders the activities of GCN. Promoting better structure organization and decreasing domain sizes are efficient strategies to boost charge carrier transfer of GCN. However, these modifications usually lead to decreased light harvesting properties. In this paper, we modified small domain-sized graphitic carbon nitride (polymerized by urea) with extended visible light absorption (by nitrogen deficiencies) as well as improved charge carrier transport behaviors (by better structure organization) through implementing post-thermal treatment for 2 min. Inspiringly, the modified graphitic carbon nitride shows improved photocatalytic hydrogen evolution activities with 78.6% that of benchmark material P25 under irradiation of λ > 300 nm as well as high hydrogen evolution activity (80 μmol h–1, 20 mg) under visible light irradiation (λ > 420 nm). This work proposes an efficient way to obtain an active GCN photocatalyst and gives important reference for the rational design of GCN