简介:ThehighlyorderedTiO2nanotubes(NTs)werefabricatedbytheanodicoxidationmethod.Theirmorphology,structureandcrystallinephasewerecharacterizedbyscanningelectronmicroscopy(SEM)andX-raydiffractometer(XRD).Theeffectsofmorphology,specificsurfacearea,porestructuresandphotocatalyticactivityoftheTiO2NTswereinvestigated.UV–visspectraanalysisshowedthatitslightabsorptionhadbeenextendedtothevisiblelightrange.Thephotocatalyticactivityoftheas-preparedsampleswasevaluatedbyphotocatalyticoxidationofgaseousHCHOandMBaqueoussolution.Thesampleshadbetteradhesionstrengthinthedarkandshowedahigherphotocatalyticactivitythannanoparticles.Especially,withultravioletlightpretreatment,thenanotubesexhibitedmorestableactiveforphotocatalyticdecompositionandthephotodecompositionrateremainedathighlevelafter3cyclesofthephotocatalysisexperiment.Thus,howthenumberofsurfaceactivegroup·OHincreasedandthemechanismforthegreatimprovementforthephotocatalyticactivityarediscussed.
简介:1.IntroductionAnimportsnttopicinQualityColltrolisthestudyofacceptancesamplingplan.Foravariablesamplingplan,thequalityofanitemismeasuredbyarandomvariable.Todesignavariablesamplingplanistodeterminethesamplesizeandthespecilicstionlicit(s).Manyschemeshav...
简介:采用气相色谱内标法测定苯酚中的有机杂质,通过用不同极性的两根毛细管柱作比较,不同的分析要求可以采用不同的毛细管柱,对苯酚的生产和用户的质量控制具有一定的指导作用,为制定企业标准苯酚中有机杂质指标提供一定的理论依据。