Oxygen doped graphitic carbon nitride with regulatable local electron density and band structure for improved photocatalytic degradation of bisphenol A

Oxygen atoms with lone pair electrons have been used to improve the photocatalytic activity of graphitic carbon nitride (g-C3N4). Herein, a one-step annealing strategy without co precursor is used to prepare O-doped graphitic carbon nitride (OCN) for photocatalytic degradation of bisphenol A (BPA). The band structure and photocatalytic performance are tuned by simply controlling the heating time. The degradation rate constant for OCN6 is improved by 29 times compared to the original CN. Experimental and the density functional theory calculated results prove that the doped-O is the key factor in promoting photocatalytic performance. The introduced O not only adjusts local electron density, but also decreases the band gap to boost e(-) transfer and carrier generation and separation. The elevated conductive band energy is responsible for producing O-2(.-), which is the dominated reactive oxygen species. This work offers a simple and effective way for the self-modification of metal-free catalysts to resolve environmental issues.