The influence of narrow optical gap silver oxide on zinc oxide nanoparticles produced by microwave-assisted colloidal synthesis: photocatalytic studies

摘要

Thispaperreportsaphotocatalyticstudyonwidebandgapzincoxide(ZnO)incorporatedbynarrowbandgapsilveroxide(Ag2O),namelyAg2O/ZnOnanocomposites,whichwerepreparedbycolloidalsynthesiswithmicrowavesupports.TheAg2O/ZnOnanocompositeswerepreparedwiththreedifferentmolarratios(MR)ofAg2OtoZnO(MR:0.25,0.5and0.75).InordertoconfirmqualitativelytheconcentrationratioofAg2OinZnO,crystalphaseintensityratiowasexecutedbypeakindexingfromx-raydiffraction.TheAg2O/ZnOnanocompositespropertieswerefurtherinvestigatedusingdiffusereflectancespectroscopy.ThenanocompositesweretestedforthedegradationoforganicdyessolutionsundervisibleandUVlightirradiations.ThephotocatalyticactivityofAg2O/ZnOnanocompositesundervisiblelightincreasedwithincreasingmolarratioofAg2OtoZnO,whiletheoppositetrendsobservedunderUVlightirradiation.Theimprovementofphotoabsorptiontogetherwithphotocatalyticactivitiesmightbesuspectedduetothep-nheterojunctionstructureinAg2O/ZnOnanocomposites.Thecorrespondingmechanismwillbediscussedindetail...