General synthesis of carbon and oxygen dual-doped graphitic carbon nitride via copolymerization for non-photochemical oxidation of organic pollutant

Abstract

Earth-abundant, environmental-benign and durable catalysts are of paramount importance for remediation of organic pollutants, and graphitic carbon nitride (g-C3N4) is a promising nonmetallic material for this application. However, the catalytic oxidation on g-C3N4 suffers from low efficiency because of its chemical inertness if not irradiated with light. Herein, we develop a facile copolymerization strategy for the synthesis of carbon and oxygen dual-doped g-C3N4 using urea as g-C3N4 precursor and ascorbic acid (AA) as carbon and oxygen sources, which induces electronic structure reconfiguration. By replacing AA with other organic precursors, a series of C and O dual-doped g-C3N4 are successfully prepared, demonstrating the generality of the developed methodology. As a demonstration, the C and O dual-doped g-C3N4 using AA as the organic precursor (CN-AA0.3) exhibits pronouncedly enhanced catalytic activity in peroxymonosulfate (PMS) activation for organic pollutant degradation without light irradiation compared with pristine g-C3N4 and single oxygen-doped g-C3N4. Experimental and theoretical results revealed the electron-poor C atoms and electron-rich O atoms as active sites for PMS activation in terms of simultaneous PMS oxidation and reduction. This work offers a universal approach to synthesize nonmetal dual-doped g-C3N4 with reconfigured electronic structure, stimulating the development of g-C3N4-based materials for diverse environmental applications.