One-step calcination synthesis of granular-like C2N3 with high visible photocatalytic activity for organic contaminant removal

Metal-free g-C 3 N 4 semiconductor has been extensively utilized as green catalyst for visible-light-driven degradation of various organic contaminants. However, its application has been constrained due to its inherent shortcomings, including weak visible light adsorption, low specific surface area and high recombination rate of electron-hole pairs. Herein, a novel carbon nitride (C 2 N 3 ) photocatalyst was synthesized via a one-step calcination method utilizing 3-amino-1,2,4-triazole (3-AT) as precursor for the first time. Unlike widely reported two-dimensional carbon nitride materials, the obtained C 2 N 3 exhibited a granular-like morphology with relatively high specific surface area. Under visible light (λ > 420 nm) irradiation, C 2 N 3 exhibited an excellent photocatalytic activity for Rhodamine B (RhB) degradation, due to its stronger visible-light absorption, faster photogenerated electron-hole separation and easier charge transfer, surpassing that of the popular g-C 3 N 4 . After 5 cycles, the degradation efficiency of RhB still remained over 94 %, suggesting high stability and reusability. Moreover, the C 2 N 3 /Vis system had high adaptabilities to temperature, solution pH and organic pollutant, even in the presence of high concentration of common matrix species like Cl − , NO 3 − , SO 4 2 − and humic acid. •O 2 − and 1 O 2 were revealed to be the main reactive species generated in the C 2 N 3 /Vis system, a combination process of radical and non-radical pathways for organic degradation. This work developed a novel granular-like C 2 N 3 material for visible light photocatalysis, which showed an incredible potential in photocatalytic degradation of organic pollutants.