Elevated degradation of di-n-butyl phthalate by activating peroxymonosulfate over GO-CoFe_(2)O_(4)composites:Synergistic effects and mechanisms

Rational design of heterogeneous catalysts with high activity and stability is crucial in peroxymonosulfate(PMS)-based oxidation treatment of wastewater.Herein,the graphite oxide-cobalt ferrite(GOCoFe_(2)O_(4))composite was constructed,and its morphological,component and structural characteristics were thoroughly examined,respectively.GO-CoFe_(2)O_(4)obviously boosted PMS catalytic performance on di-n-butyl phthalate removal(DBP,RpBp=90%,Roc=37%),which indicated by the first-order kinetic constant(kpBp=0.060 min^(-1))being roughly 4 times than pure CoFe_(2)O_(4)(kpBp=0.015 min-1).The fabrication of GO-CoFe_(2)O_(4)brought the favorable stability and repeatability up to six cycles.Moreover,the method of batch dosing catalyst was creatively proposed to improve the PMS utilization efficiency.The coupling of GO enhanced the dispersion of CoFe_(2)O_(4)particles to obtain sufficient active sites,additionally,the plentiful C=O groups and free-flowing electrons on GO promoted GO-CoFe_(2)O_(4)to coordinate a redox process during PMS activation.With the aid of theoretical calculations,GO-CoFe_(2)O_(4)was revealed to exhibit a strong affinity toward PMS adsorption,where PMS spontaneously dissociated into sulfate radical(SO_(4)^(·-)),hydroxyl radical(^(·)OH)and singlet oxygen(^(1)O_(2)),acting as the reactive oxygen species(ROSs).Electrons cycling between Co,Fe and O species ensured continuous ROSs generation and excellent catalytic performance.

Facile preparation ofα-MnO_(2)nanowires for assembling free-standing membrane with efficient Fenton-like catalytic activity

Assembling MnO_(2)nanowires into macroscopic membrane is a promising engineered technology for catalyst separation and enhancement of Fenton-like reaction activity,yet its development is limited by the deficiencies in preparation and property modulation of the MnO_(2)nanowires.In this work,we developed a facile method using C_(2)H_5OH and CH_(3)COOK as reductive and vital control reagents to react with KMnO_(4)by hydrothermal reaction at 140℃for 12 h,to prepare the ultralongα-MnO_(2)nanowires up to tens of micrometers with high purity and aspect ratio.Such strategy not only had the advantages of being mild,easily controlled and environmental pollution-free,but also endowedα-MnO_(2)nanowires with excellent ability as a Fenton catalyst when assembled into free-standing membrane for degrading phenolic compounds(k_(obs)=0.0738~0.1695 min^(-1))in a continuous flow reaction.The reactive oxygen species(i.e.,~·OH)from Fenton-like reaction were enriched within thisα-MnO_(2)nanowire membrane via nanoconfinement effect,which further enhanced the mass transportation of~·OH available for phenolic contaminants.MnO_(2)nanowire membrane using our method possessed the high practical potential for water purify due to its easy-preparation and enhanced catalytic performances.