Synthesis Of Iron Loaded Mesoporous Carbon And Application For Heterogenous Fenton Degradation Of Organic Pollutants

In this study,we synthesized three different Fenton catalyst by using hydrophilic mesoporous carbon?HMC?as catalyst support.Fe???-HMC was synthesized by impregnating HMC in ferric nitrate solution.The ferric ions were strongly interacting with carboxylic groups via flexible coordination in the HMC frameworks.Ferrihydrite immobilized on HMC named as Fhy/HMC and goethite??-FeOOH?immobilized on HMC named as?-FeOOH/HMC were synthesized by hydrothermal treatment of Fe???-HMC.Phenol was selected as model contaminant and catalytic activity was characterized by degradation and mineralization efficiency of phenol.It was found that Fe???-HMC performed stable and high catalytic ability.Fe?III?-HMC showed obviously enhanced phenol degradation and mineralization efficiencies under visible light than that in dark condition.The heterogenous Fenton degradation of phenol over Fe???-HMC could operate at wide pH values?pH 3-9?while higher removal efficiency was achieved under acidic conditions with barely iron leaching.TOC removal of five different organic pollutants showed that visible light active Fe?III?-HMC catalyst was more efficient than homogeneous Fenton reagents FeSO₄/H₂O₂ excluding the temperature effect.Exploring the effect of hydrothermal time on Fhy/HMC,it was found that Fhy particle size got larger with longer hydrothermal time.However,Fhy/HMC with small Fhy nanoparticles encapsulated in the HMC frameworks showed the highest heterogeneous Fenton performances.The sufficient active sites of Fhy nanoparticles and efficient electron shuttle effect from HMC surface were responsible for the high catalytic activity.For?-FeOOH/HMC,the visible light active?-FeOOH nanocrystals were encapsulated in the mesoporous frameworks via C-O-Fe bonding.Visible light could improve the heterogenous Fenton catalytic activity of?-FeOOH/HMC.The reused?-FeOOH/HMC composites showed much higher phenol oxidation and mineralization efficiencies than the fresh catalyst and the XPS,XRD,FTIR and N₂ adsorption measurements were carried out to investigate the interesting phenomenon.Through the recycling experiments,it was proved that the three catalysts could be used repeatedly with stable performance.Furthermore,the produced radicals and valence of iron ions were examined to elucidate the mechanism for degradation of organic pollutants in these three heterogenous Fenton reaction.Therefore,we established a new type of heterogeneous Fenton system in which HMC was used as supports and it improved the performance of heterogeneous Fenton catalyst for the treatment of emerging organic pollutants.Meanwhile,we provided a theoretical basis for the application of Fenton technology in organic pollutants removal in wastewater.