Study On The Preparation And Catalytic Properties Of Bimetallic Iron-nickel Catalyst

In recent years,highly active free radicals have been widely used in environmental remediation,biosensor,material synthesis and other fields.Particularly,controllable and efficient sulfate radical（·SO₄^-）produced by Fenton-like process is widely used to treat persistent organic pollutant.During the process of sulfate radical based advanced oxidation technology,the generation of sulfate radicals requires high redox potential of the M^{（n+1）+}/Mⁿ⁺redox cycle in transition metal catalysts.In this study,iron was introduced into the layered hydroxide of nickel（Ni LDH）by hydrothermal method to prepare the bimetallic iron-nickel layered hydroxide（FeNi LDH）with redox potential high enough to activate persulfate.The introduction of iron promoted the charge transfer of the conversion from trivalent nickel ions to divalent nickel ions,inhibited the formation of highly oxidized nickel,enhanced the cycling process of Ni（OH）₂/Ni OOH redox,and improved the catalytic performance of FeNi LDH.The phenolic pollutant bisphenol A was selected as the typical pollutant,and the degradation rate of 100 mg/L bisphenol A was over 99%in 20 minutes.This study opens up a new way for advanced oxidation technology based on sulfate radical and expands the application of LDH materials in environmental remediation.In addition,the bimetallic ferric nickel sulfide（FeNiS）obtained from the sulfurization of FeNi LDH by simple hydrothermal method is also found having excellent degradation performance of organic pollutants containing chlorine.The ability of FeNiS nanoparticles to activate persulfate and produce sulfate radical to degrade pollutants was also investigated by using persulfate as oxidant.The results showed that FeNiS nanoparticles could effectively degrade chlorined organic pollutants such as 4-monochlorophenol,1,4-dichlorophenol and 2,4,6-trichlorophenol by activating persulfate.Within 20 minutes,50 mg/L of 2,4,6-trichlorophenol was degraded to 100%,and the dechlorination efficiency and TOC removed rate are also reached above 80%.Sulfate radical has strong oxidation dechlorination ability and hydroxyl radical production ability under basic conditions,which plays a leading role in the whole catalytic process.At the same time,during the dechlorination process,the chlorine ions removed from the chlorined organic pollutants can be converted into chlorine radicals,further promoting degradation and mineralization.In this part of work,FeNiS nanoparticle was proposed and experimentally verified to be a promising catalyst in the field of effective activation of persulfate and degradation of chlorinated organics.