3D-TNAs/N-TiO2 photoanode assisted heterogeneous electro-Fenton with a novel Fe-MOFs@CF cathode for efficient synergetic oxidation of organic contaminants

Abstract

Photoelectro-catalysis (PEC) and heterogeneous electro-Fenton (HEF) reactions are two frontier research fields for real effluent treatments. In the present work, a synergetic system with integration of both PEC and HEF has been developed for pollutant removal. PEC process with lower external bias results in the efficient separation of photogenerated hole and electrons, which can also modulate the HEF catalytic performance at the counter electrode, and in other cases the active HEF reaction can in turn affect the intrinsic activity of PEC. In this system, three dimensional TiO2 nanotube arrays coupled with nitrogen doped TiO2 nanoparticles (3D-TNAs/N-TiO2) was prepared as photoanode for solar light-driven PEC process while NH2-MIL-101 loaded on carbon felt (Fe-MOFs@CF) have been used as the cathode for HEF reaction. The performances of the synergetic system showed much higher degradation efficiency, which were evaluated by degrading typical organic containments in water (with the best of∼95 % in 5 min with 2*3 cm2 electrode area). The reaction rate in the coupling system were ∼7.25 and 1.18 times higher than single PEC or HEF with a wide pH applied range, well recycled and good stability for further application in water purification.