A metal-free visible light active photo-electro-Fenton-like cell for organic pollutants degradation

Abstract

To avoid the potential secondary metal pollution leached from Fenton-like catalysts and use less or no external chemicals supply, we develop an all-carbon based visible light active photo-electro-Fenton-like (PEF) cell to in-situ generate highly active •OH radical for environmental remediation. In this cell, the mesoporous carbon coated graphite felt (MesoC/GF) cathode could effectively produce H2O2 by electrochemical reduction of oxygen. Graphitic carbon nitride (g-C3N4) with visible light photocatalytic activities acts as an efficient metal-free Fenton-catalyst for H2O2 activation to produce •OH radical under visible light irradiation. The different cell parameters such as applied voltage, photocatalysts dosage and pH condition have been investigated for phenol removal in aqueous solution. This metal-free visible light active PEF cell shows excellent mineralization efficiency of stubborn phenol with high stability and its performance of phenol removal efficiency is much higher than that of the g-C3N4 only photocatalysis cell and MesoC/GF only electrolysis cell. Moreover, our PEF cell presents comparable or even better Fenton-catalytic activities than the similar electro-Fenton cell using MesoC/GF and homogeneous Fe2+ ion. These results demonstrate our all-carbon based PEF cell without external chemicals supply is promising for environmental remediation.