A novel graphene-N/TiO2-nickel foam: Preparation and application in photoelectric synergistic degradation of methyl orange

Abstract

Photoelectric synergistic degradation of dye wastewater has been developed. In this experiment, we prepared Nitrogen-doped titanium dioxide-graphene/nickel foam (N/TiO2-Gr/F–Ni) by electrophoresis and impregnation methods, to degrade methyl orange (MO) aqueous solution. Firstly, nitrogen-doped titanium dioxide particle (N/TiO2) was prepared by the sol-gel method, which showed a photocatalytic degradation catalytic kinetic constant of 1.8 × 10−2 min−1 under simulated sunlight. Meanwhile, graphene (Gr) was loaded on nickel foam (F–Ni) to prepare Gr/F–Ni electrode by electrophoresis method, which obtained a catalytic kinetic constant of 1.15 × 10−2 min−1 at 10 V. Finally, N/TiO2 was loaded on Gr/F–Ni to prepare N/TiO2-Gr/F–Ni photoelectrode by electrophoresis and impregnation methods, which had a catalytic kinetic constant of 3.96 × 10−2 min−1 at 10 V and under 1 sun. The results show that there is a synergistic effect between light degradation and electro-Fenton oxidation because the bonding electrons in N/TiO2 are activated to produce photogenerated electron-hole pairs. On the other hand, the separation efficiency of the photogenerated electron is enhanced by the Gr.