Ni, Fe, and N-tridoped activated carbon as a highly active heterogeneous persulfate catalyst toward the degradation of organic pollutant in water

Abstract

The Ni, Fe, and N-tridoped carbon catalyst was synthesized by a sequential impregnation method. The Fe oxides, Ni oxides, zero-valent Fe, N species and Fe-Nx were simultaneously present on the surface of the catalysts. Both metal composition and N dopants enhanced the catalytic activity, and 89.0% of the methyl orange (MO) was removed over 4Ni2Fe@20NAC. The introduction of Ni resulted in the reduction of iron oxides and the generation of more zero-valent iron, which greatly improved the catalytic activity. The doping of N led to the formation of pyridinic N, graphitic N and Fe-Nx species, which were beneficial to the catalyst activity and stability. The surface-bound OH and SO4– generated from the N-doped carbon played a predominant role in the degradation of MO. The catalyst recycling showed MO removal was about 80% over 4Ni2Fe@20NAC after the fifth running.