g-C3N4 modified by hydroxyl group on the surface prepared by double salt enhanced the visible light photocatalytic activity

In this paper, g-C 3 N 4 was modified by the synergistic effect of double salt KCl-(NH 4 ) 2 CO 3 , and porous g-C 3 N 4 with hydroxylated surface was prepared. Combined with a series of characterization (XRD, SEM , BET, FTIR, UV–vis DRS and XPS) and density functional theory (DFT) analysis, it is confirmed that KCl can cooperate with ammonium salt (NH 4 ) 2 CO 3 to produce rich pore structure , and (NH 4 ) 2 CO 3 , as an alkaline slow-release agent, can assist KCl to further enhance hydroxylation . KCl-(NH 4 ) 2 CO 3 not only plays a synergistic role in pore formation, but also introduces hydroxyl and cyano groups, which improves the hydrophilicity of g-C 3 N 4 , promotes the separation efficiency of photo-generated carriers, and is beneficial to enhance the photocatalytic activity . Taking methyl orange (MO) as the model of pollutant degradation, and proposed the possible degradation mechanism . This study provides a simple, efficient and widely applicable method for modifying g-C 3 N 4 to improve its activity.