An efficient broad spectrum-driven carbon and oxygen co-doped g-C3N4 for the photodegradation of endocrine disrupting: Mechanism, degradation pathway, DFT calculation and toluene selective oxidation

Abstract

In this study, a new type of carbon and oxygen co-doped g-C₃N₄ (PACN) was successfully synthesized by a one-step thermal polymerization method for the photodegradation of Bisphenol A (BPA) and selective oxidation of toluene to benzaldehyde. The degradation rate of BPA was 23.58 times higher than that of pristine g-C₃N₄ and the efficiency benzaldehyde formation rate without the need of any solvent increased to 5.43 times that of g-C₃N₄. At the same time, the band structure calculation of its simulated structure is performed by DFT, which shows that the introduction of oxygen linking band can adjust its band structure and obtain a smaller band gap. In addition, the PACN displays an enhanced photocatalytic degradation of BPA under the long wavelength (λ ≥ 550 nm) and NIR light irradiation (λ ≥ 760 nm), which indicates that the synthesized materials have a broad spectrum of photocatalytic activity. According to the results of secondary ion mass spectrometry (SIMS) and nuclear magnetic resonance spectroscopy (NMR), C atoms and O atoms were introduced into the original g-C₃N₄ skeleton. In addition, the intermediate products were detected by mass spectrometry (HPLC-MS), and the BPA degradation pathway was proposed. A feasible photocatalytic reaction mechanism was also proposed.

Keywords: Benzaldehyde; Bisphenol A; DFT; Degradation; PACN.