Enhanced visible light photocatalytic activity of g-C3N4 via the synergistic effect of K atom bridging doping and nanosheets formed by thermal exfoliation

In this study, a type of novel K doped g-C3N4 nanosheets (KCNN) was synthesized by combining K atom bridging doping and thermal exfoliation for the first time. The as-synthesized KCNN had a very efficient ability of photocatalytic degradation of RhB by visible light, and its catalytic rate constant was 8.3 times higher than that of pure g-C3N4. This excellent photocatalytic performance came from the bridging doping of K atom and the morphology of the KCNN nanosheets. The KCNN nanosheets not only had the advantage of the large specific surface area, but also enhanced the electron-hole separation by shortened charge-to-surface migration length. In addition, the bridging doping of K atom increased the absorption of visible light, and promoted the separation of electron-hole due to electrostatic and bridging effects. Our work not only provided a promising material for effective removal of dye contaminants from wastewater but also opened a new window for the mechanism of electron and hole (e(-) and h(+)) separation in doped modified and dimensionality tuning materials.