The Influence of Morphology on Photo-catalytic Activity and Optical Properties of Nano-crystalline ZnO Powder

摘要

ZnOnano-particlesweresynthesizedviaanammonicalammoniumcarbonatesolutionbyprecipitationmethodinpresenceofsomeadditivessuchasurea,oleicandstearicacid.Themorphologyandcrystallinityoftheobtainedzincoxideparticlesdependcriticallyonthetypeofadditivewhichwasused.Additivesalsoaffectedthecrystalorientationofprecipitatenano-particles.SEM,XRD,BETandUV-visiblewereusedtocharacterizemorphology,microstructure,specificsurfaceareaandopticalpropertiesoftheproducts.Photo-catalysispropertiesoftheas-preparedZnOpowderswereevaluatedbydegradationofmethylred(acidred)inaqueoussolutionexposedtoUV-light.Resultssuggestedacloserelationshipamongthemorphology,sizeandsurfaceareaonphoto-catalysisandopticalpropertiesoftheparticles.ThewidestEgvalue(3.56eV),highestdegradationanddecolorizationefficiency(99%)wereobtainedfromasamplewiththesmallestgrainsize(largestsurfacearea)whichwereusedureaasanadditive.