Degradation of levofloxacin by electro-Fenton with CNT supported nano-iron cathode
Carbon nanotubes(CNT)were modified using concentrated sulfuric acid,and the modified CNTs(MCNT)were employed as the support for iron(MCNT-Fe)to construct a heterogeneous electro-Fenton system with the cathode of MCNT-Fe for the removal of levofloxacin(LFV).Characterization results of the cathode material by SEM,XPS,XRD,and FTIR revealed that the loaded iron existed in the form of nano-Fe2O3 with the majority of particles(＞80％)being smaller than 8nm,while various oxygen-containing functional groups were found on the surface of MCNT.Analysis of the cyclic voltammetry curves(CV)and impedance spectra(EIS)of the cathode materials indicated that the MCNT-Fe cathode exhibited greater oxygen reduction activity and stronger electron transfer capability than CNT and MCNT.Consequently,the electro-Fenton with the MCNT-Fe cathode demonstrated higher LFV removal efficiency.Under optimized conditions,the LFV removal efficiency could reach 92.7％～95.7％in range of pH 3～9 after 240min reaction.The Singlet oxygen(1O2)was identified as the primary reactive oxygen species(contributing to 64.6％).Furthermore,the MCNT-Fe cathode exhibited stable performance during multiple cycles with LFV removal rate of 89.3％after six cycles.The expanded pH range,stable cathode performance,and excellent LFV removal performance make the electro-Fenton method with MCNT-Fe cathode highly suitable for practical application.The proposed mechanism for the formation of 1O2 provides theoretical support for its application.
万方数据
维普
