Promoting photo-Fenton reactions by anchoring Fe doped g-C3N4 onto an amidoxime-functionalized fibrous support for organic contaminants removal

Abstract

Fe-doped graphitic carbon nitride (g-C3N4) represents an attractive photo-Fenton catalyst for organic contaminants removal, but the practical performances still need to be improved for large-scale application. Herein, we developed a high-efficiency photo-Fenton catalyst by anchoring Fe-g-C3N4 onto an amidoxime-functionalized polyacrylonitrile fiber (AP) substrate through a simple hydrothermal approach. Comprehensive characterizations demonstrate the strong catalyst-support interaction via the axial coordination bonding between -OH groups and Fe3+, which could induce electric polarization of Fe-g-C3N4 to promote the H2O2 adsorption and activation. The fibrous support could also accelerate the photoelectrons transfer from g-C3N4 to Fe3+ by strengthening the d-π conjugated large π bond, as well as alleviate the backflow recombination from Fe3+ to g-C3N4 through the electron sink effect. These synergistic qualities resulted in superior photo-Fenton performance for organic contaminants removal, which delivered 4.0-fold higher degradation kinetics than that of the Fe doped g-C3N4 powder catalyst and exhibited unexpected high activity at strong basic environment (pH = 12). Our work demonstrates an ingenious and simple way to design exceptional photo-Fenton catalysts for environmental remediation.