A novel method to synthesis of oxygen doped graphitic carbon nitride with outstanding photocatalytic efficiency for the degradation organic pollutants

Contamination of water sources with organic pollutants seriously threatens the environment and living organisms, so it is necessary to remove them from these sources with a proper method. Photocatalytic degradation of such pollutants can be an effective, low-cost and eco-friendly method. In this study, a new method, porous oxygen-doped Graphitic carbon nitride (POCN) photocatalyst was synthesized by pre-exfoliation of bulk graphitic carbon nitride in hydrogen peroxide followed by calcination of the resulting exfoliated and oxygenated sample at 550 °C. In fact, in this method, a combination of three strategies, nanostructure preparation, band gap engineering and defect introduction into the g-C3N4 were used to improve the efficiency of photocatalyst. The synthesized sample was characterized using XRD, FESEM, TEM, FTIR, DRS, PL, EDX, XPS, and BET-EJH. The efficiency of the prepared photocatalyst was evaluated with its ability to degrade Congo Red (CR) in aqueous solution under visible light using two light sources, LED lamp and daylight. POCN removed the CR in a short time. The degradation rate was higher under sunlight. The free radical trapping tests showed that superoxide radical anions (O2−) are the active species and are mainly responsible for color degradation. [Display omitted] •A large surface area with a lot of porosity and abundant active sites•The better oxygenation•High optical activity under sunlight•Strong suppression of recombination photoinduced electron-hole pairs