Improvement of the catalytic performance of Fe/Mn Co-doped graphitic carbon nitride (g-C3N4) via homojunction generation

The rational design and fabrication of high-efficiency catalysts for Fenton-like reactions have become a central research direction. As a recently emerging catalyst of great interest, the catalytic performance of bimetal-doped g-C 3 N 4 (graphitic carbon nitride) is still limited by the electron transfer. In this study, Fe and Mn co-doped g-C 3 N 4 (designated as Fe/Mn-CCN) was prepared via a co-sintering method, which an internal electric field was formed via a homojunction generation from the introduction of cyano groups (-C N) in Fe/Mn-CCN, enhancing electron transfer and catalytic activity for the degradation of tetracycline (TC) through the Fenton-like reaction. Simultaneously, it modulated the electronic density of metal active sites to enhance the adsorption capacity for TC and PMS. The rate constant of the reaction is 4.34 times higher than that of the pristine bimetallic catalyst (Fe/Mn-CN). The turnover number (TON) of Fe/Mn-CCN reaches as high as 32 × 10 −4 (g/L min) −1 , outperforming most reported graphitic carbon nitride (g-C 3 N 4 )-based catalytic systems with a significant enhancement in catalytic efficiency. Furthermore, the degradation efficiency retains 90% after continuous cyclic reactions for 12 h, demonstrating its excellent structural stability. This study provides a new perspective for the development of environmentally friendly materials used in pollutant degradation.