Activation Of Peroxymonosulfate By CoMoO₄ For Degradation Of Organic Dyes

In recent years,the pollution of environment problem is becoming more and more serious with the rapid development of industry,and this issue should cause great harm to human health of body and mind.Hydroxy radicals-based Fenton technology were studied widely due to its high oxidative potential,but the narrow pH range still restricted their development.Hence,peroxymonosulfate as a source of sulfate radicals(SO4·-)has received much attention,ultraviolet radiation and transition mental ions activation are used to generate SO4·-,which can degrade organics.In this work,we prepared metallic oxide-CoMoO4,which has high electrochemical performance,and employed it as a novel heterogeneous catalyst for PMS activation to release the powerful sulfate radicals for the first time.In addition,the effects of some potential influential factors,the catalytical mechanism were systematically evaluated.CoMoO4 percursor was prepared by a hydrothermal method,XRD、SEM and other methods were used to record sample.The material has uniform microstructure and high catalytic property,after calcination under muffle,the precursor transferred into β-CoMoO4 finally.Selected different calcination temperature and evaluate the property of several samples,chose the better one for experiment behind.The sample calcined after 500°C has uniform flower-like structure,and its surface area is 61.9 m2/g,the large BET area provided high catalytic property for CoMoO4.Methyl blue(MB)is selected as a model organic pollutant,and it is found that CoMoO4/PMS system can realize 100% degradation of MB in 40 min,which is better than Co3O4 and CoFe2O4.Meanwhile,CoMoO4 can maintain its removal efficiency during three recycling experiments.The effects of some potential influential factors,including dosages of PMS and CoMoO4,reaction temperature and the initial pH value systematically evaluated.And bicarbonate,natural organic matter,metal ions also has effect to this catalytic system.Two reasons of the influence are proposed,including effect the generation of radicals or react with radicals.Surface water and tap water are chosen as the background conditions,CoMoO4 still exhibits considerable degradation effeciency.More importantly,CoMoO4/PMS system not only shows its universality in the degradation of other organic dyes,particularly to anionic dye.The classical quenching tests are carried out to figure out the specific reaction mechanism in the system of MB degradation,confirms that sulfate radicals and hydroxide radical are the main active species for the degradation of dyes.During the activation of PMS,Co sites on the surface of CoMoO4 play primary active sites for the transfer of electrons.The transfer of electrons occurs on Co(II)on the surface of CoMoO4 and generate the radicals,and then radials react with organic.