One-step synthesis of oxygen doped g-C3N4 for enhanced visible-light photodegradation of Rhodamine B

O-doped g-C 3 N 4 (denoted as x-OCN, where x is the volume of 30% H 2 O 2 for a given amount of urea) materials were prepared by calcining dried the mixtures of urea impregnated with H 2 O 2 at 550 °C. The characterization shows that the x-OCN materials are formed by replacing N in g-C 3 N 4 by O atoms, which is further supported by density functional theory calculations. The rhodamine B photodegradation performance on the x-OCN materials is higher than the pure g-C 3 N 4 . Among the x-OCN samples, 40-OCN shows the strongest photocatalytic activity, which could be attributed to the largest content of doped-O in the matrix of g-C 3 N 4 , leading to a reduced bandgap energy and a lower recombination rate of photogenerated electrons and holes, therefore enhancing the photocatalytic performance. The mechanism for the photocatalytic degradation of RhB was proposed based on the investigation on the role of active species and the pathway of RhB degradation. • O-doped g-C 3 N 4 materials were prepared. • The photocatalytic performance for the materials was investigated. • The doping O in g-C 3 N 4 lead to an improvement in its photocatalytic performance.