Nitrogen doped BiFeO3 with enhanced magnetic properties and photo-Fenton catalytic activity for degradation of bisphenol A under visible light

In the present work, N doped BiFeO3 (N-BFO) nanoparticles have been synthesized via a sol-gel rapid calcination technique using melamine (C3H6N6) as the N precursor. It is found that N-doping could effectively narrow the band gap of BFO, which obviously enhanced the visible light adsorption capability. Meanwhile, N-doping could lead to significant increase in the magnetization of BFO. Particularly, the saturation magnetization (Ms) was increased up to 0.35 emu/g (as compared to that of pure BFO: 0.07 emu/g) when 12.5 mmol N doping precursor was used (12.5N-BFO). The catalytic performance of N-BFO nanoparticles was evaluated through the degradation of bisphenol A (BPA) under visible light irradiation. 12.5N-BFO was found to be an efficient catalyst of BPA, and the addition of H2O2 (10 mmol/L) or H2O2 (10 mmol/L)/l-cysteine (0.25 mmol/L) can further enhance the degradation efficiency up to 60% and 94% within 120 min, respectively. The 12.5N-BFO nanoparticles were very stable during photocatalytic processes and their photo-Fenton catalytic activity can be retained even after three recycling processes.