Modification of the electronic structure of g-C 3 N 4 using urea to enhance the visible light-assisted degradation of organic pollutants.

Graphitic carbon nitride has been proven to be a good candidate for using solar energy for photo-induced pollutant degradation. However, the high photo-induced holes-electron recombination rate, unfavorable morphology, and textural properties limited their application. In this study, we present a novel g-C 3 N 4 with a novel electronic structure and physiochemical properties by introducing a single nitrogen in the graphitic network of the g-C 3 N 4 through a novel method involving step-by-step co-polycondensation of melamine and urea. Through extensive characterization using techniques such as XPS, UPS-XPS, Raman, XRD, FE-SEM, TEM, and N 2 adsorption-desorption, we analyze the electronic and crystallographic properties, as well as the morphology and textural features of the newly prepared g-C 3 N 4 (N-g-C 3 N 4 ). This material exhibits a lower C/N ratio of 0.62 compared to conventional g-C 3 N 4 and a reduced band gap of 2.63 eV. The newly prepared g-C 3 N 4 demonstrates a distinct valance band maxima that enhances its photo-induced oxidation potential, improving photocatalytic activity in degrading various organic pollutants. We thoroughly investigate the photocatalytic degradation performance of N-g-C 3 N 4 for Congo red (CR) and sulfamethoxazole (SMX), and removal of up to 90 and 86% was attained after 2 h at solution pH of 5.5 for CR and SMX. The influence of different parameters was examined to understand the degradation mechanism and the influence of reactive oxygenated species. The catalytic performance is also evaluated in the degradation of various organic pollutants, and it showed a good performance.