Highly disordered g-C3N4 with abundant carbon defects boosting photocatalytic tetracycline degradation

Modulating electronic structure to improve photocarriers (photo-generated electrons and holes) separation and suppress photocarriers recombination is crucial for developing highly-active g-C 3 N 4 photocatalyst to degrade tetracycline for alleviating environmental pollution. In this work, a highly disordered g-C 3 N 4 catalyst with abundant carbon defects has been developed via optimization of the precursor composition. The g-C 3 N 4 -M 1 C 2 , prepared by pyrolysis of mixed melamine/cyanuric acid precursors with the molar ratios of 1:2, possesses more sensitive photocurrent response, lower recombination of photocarriers and more negative potential of conduction band as compared to other g-C 3 N 4 catalysts. These enhance the photocarrier-production efficiency and promote the formation of superoxide radicals, thus boosting the photocatalytic tetracycline degradation performance. During a 90-min tetracycline degradation reaction catalyzed by g-C 3 N 4 -M 1 C 2 , the degradation ratio reaches about 87.0 %, demonstrating a substantial improvement in photocatalytic performance as compared to other investigated g-C 3 N 4 catalysts (g-C 3 N 4 -M, g-C 3 N 4 -C and g-C 3 N 4 -M 2 C 1 , which are prepared by pyrolysis of melamine, cyanuric acid and mixed melamine/cyanuric acid precursors with the molar ratios of 2:1, respectively). This work opens up new opportunity of developing high-performance g-C 3 N 4 catalysts by modulating electronic structure through optimization of precursor composition.