简介:Aone-pot,solvent-thermalprocesswasusedtocreatetheultrafineZnFe2O4nanoparticlesphotocatalyst.Duringthesolvent-thermalprocess,theinsituself-formingNaClnotonlyservedasa"cage"toconfinetheiondiffusion,butalsoactedasamicroreactorfornanocrystallitegrowth.Anaverageparticlesizeof~10nmandahigh-specificsurfaceareaof~112.9m2/gwereobservedfortheultrafineZnFe2O4nanoparticlesOwingtothesynergisticeffectofultrafineparticlesize,thefullutilizationofthevisiblelightregionandhighconductionband(CB)position,ultrafineZnFe2O4photocatalystdisplayedanefficientphotocatalyticCO2reductionundervisiblelightillumination.Besides,theultrafineZnFe2O4photocatalystshowedhighproductionselectivityforCH3CHOandC2H5OHgenerationinaqueousCO2/NaHCO3solution.Thisworkmayprovideanewideaforthesynthesisofnewhigh-efficiencyphotocatalysts.
简介:Sodiumparanitrophenolatedihydrate(NPNa·2H2O)isanexcellentsemiorganicnonlinearoptical(NLO)material,crystallizesbothinwaterandmethanolwithhighdegreeoftransparency.Goodopticalqualitysinglecrystalsofdimensionupto18mmx6mmx3mmareobtainedbyisothermalsolventevaporationtechnique.Thesolubilityofthecrystalindifferentsolventswasmeasuredgravimetrically.ThesinglecrystalsofNPNa·2H2Oshowvariationinphysicalpropertiesandgrowthrateindifferentsolvents.Methanolorethanolsolutionyieldscrystalsofbipyramidalshapewithclearmorphology.However,methanolgrowncrystalisexhibitingimprovedhardnessparametersandpossessesexcellentthermalstabilityascomparedtowatergrowncrystals.TheeffectsofsolventonhardnessparameteralongwiththermalandopticalpropertiesofNPNa·2H2Owasrevealedinthispaper.
简介:LiMn2O4wassynthesizedrapidlybymicrowaeheating.Theproductphasesofthemicrowavesynthesisandconventionalsolid-statesynthesiswerecomparativelyinvesitigated.Thecapacityofmicrowavesynthesisproductdecreasesrelativelyslow.Thelithiumioncanbeinsertedintoandextractedfromthespinelframeworkstructurefluentlyaftercycling.Butthecapacityoftheconventionalsolid-statesynthesisproductismoreremarkablylowered.Thespinelframeworkstructurewasdestroyedwhichhinderedthelithiumionfrominsertingandextracting.Theinfluentialfactorsoftheprocessparametersarediscussedsuchasheatpreservationtime,pre-heatingat400℃for24handcoupledagent.
简介:一篇小说荧光灯为H2PO4-基于碳dots/Fe3+被设计并且制作合成。碳点被一个确定的一个壶综合热水的方法并且由传播电子显微镜,X光检查衍射计,紫外力的吸收分光计和荧光分光光度计描绘了。碳dots/Fe3+合成被碳点和FeCl3,的水的混合获得,它的荧光性质被荧光分光光度计描绘。碳点的荧光被水的Fe3+阳离子熄灭,导致碳dots/Fe3+的低荧光紧张合成。在另一方面,H2PO4-由化学反应减少了Fe3+的集中并且提高了碳dots/Fe3+的荧光合成。Stern-Volmer方程被介绍描述在合成的碳dots/Fe3+和H2PO4-,和好线性(R2=0.997)在H20.4-12公里的PO4-集中。
简介:ZnMn2为抵抗随机存取存储器(RRAM)的O4电影被磁控管劈啪作响与不同设备结构制作。I-V特征,抵抗切换行为,耐力和ZnMn2O4电影被调查。ZnMn2象底部电极的O4电影,使用的希腊语的第二十三个字母和磅,展出双极的抵抗切换(BRS)行为处于低抵抗状态(LRS)处于高抵抗状态(HRS)和细丝传导机制由space-charge-limited传导(SCLC)统治了机制,但是ZnMn2用底部电极展出双极、单极的抵抗切换行为的n-Si的O4电影在幼虫由Poole-Frenkel(P-F)传导机制控制了Ag/ZnMn2O4/p-Si设备拥有最好的耐力和保留特征,交换周期的稳定的重复的数字在是超过1000,保留时间比106秒长。然而,最高的RHRS/R104的LRS比率和最低V在和V离开3.0的,V在Ag/ZnMn2O4/Pt设备。不过Ag/ZnMn2O4/n-Si设备也拥有最高的RHRS/R104,的LRS比率但是V在,V离开,RHRS和R象差的耐力一样的LRS,并且保留特征。
简介:Inthisstudy,theeffectofmulti-walledcarbonnanotubes(MWCNTs)additiveonthedehydridingpropertiesoftheZn(BH4)2/NaCIcompositepreparedbyhighenergyballmillingwereinvestigated.X-raydiffraction(XRD),Fouriertransforminfraredspectroscopy(FTIR)resultsdemonstratedthatZn(BH4)2wasproducedfrommechanochemicalreactionbetweenZnCI2andNaBH4.Comparedwiththeundopedsample,10wt%MWCNTseffectivelyloweredthedecompositiontemperatureofZn(BH4)2by15℃.Thecomplexreleased3.6wt%hydrogenwithin250sat100℃andtotallyreleased4.5wt%hydrogenwithin2500s,indicatingithasaconsiderablepotentialasahydrogenstoragematerial.
简介:
简介:Thesol-gelprocessofcitricacidchelatingwithmetalcationsforthesynthesisofnormalspinelLiMn2O4andthereactionmechanismwereinvestigatedbymeansofXRD,IR,TG-DTA,andSEM.Theresultsshowthatatthebeginninglithiumcitrateandchelatecompoundofcitricacidwithmanganeseionsformed,andthenwithheatingtheesterificationandcondensationreactionsoccuredbetweenthemandglycol.TheproductsobtainedarepolymersinwhichmetalcationsaredistributedhomogeneouslyonatomicscalethatensurehighreactivitytocationsofLi+andMn2+.Firingthegelpreparedbythisprocess,thelatticediffusionsofsolidreactantionscausedbynon-homogeneityofreactantsareeliminatedandavoided.At400℃phase-pureLiMn2O4withnanometerscalecrystallizationhavingprecisestoichiometryandperfectcrystallizationcanbeobtained.Themodelofchelatecoordinateofdouble-moleculebetweencitricacidandMn2+inthegelnetworkisproposed.ItisimportantforexplainingthedispersionstateofMn2+andtheformationprocessofgelbythismodel.
简介:Si_3N_4-Si_2N_2Ocomposites被液相sintering(LPS)与非结晶的缩放nano的氮化矽粉末制作。Si_2N_2O阶段被in-situreaction2Si_3N_4(s)+1.5O_2(g)=3Si_2N_2O+N_2(g)产生直到在体积的60percent的Si_2N_2O阶段的内容在1650t的sintering温度被获得并且当sintering温度增加了或减少时,减少了,显示反应是可逆的。集体损失,相对密度和平均谷物尺寸与增加sintering温度增加了。当sintering温度在1700degC下面时,Theaverage谷物尺寸是不到500nm。Thesintering过程包含复杂结晶化和阶段转变:非结晶的氮化矽->equiaxialalpha-Si_3N_4->equiaxial->Si_3N_4->杆--相似Si_2N_2O->像针的beta-Si_3N_4。小回合--塑造的beta-Si_3N_4粒子在Si_2N_2O谷物被骗诱,界定差错的高密度位于在1650degC的sintering温度的Si_2N_2O谷物的中间。坚韧在1600degCto7.2MPa从3.5Mpa中心点m~(1/2)增加了在1800degC的中心点m~(1/2)。坚硬在1600degC象21.5GPa(Vickers)一样高。
简介:
简介:ThethermodynamicphasestabilityareadiagramsofBCl3-NH3-SiCl4-H2-ArsystemwereplottedviaFactsagesoftwaretopredictthekineticexperimentalresults.Theeffectsofparameters(ie,partialpressureofreactants,depositiontemperatureandtotalpressure)onthedistributionregionsofsolidphaseproductswereanalyzedbasedonthediagrams.Theresultsshowthat:(a)Solidphaseproductsaremainlyaffectedbydepositiontemperature.TheareaofBN+Si3N4phaseincreaseswiththetemperaturerisingfrom650to900℃,anddecreaseswiththetemperaturerisingfrom900to1200℃;(b)Whentemperatureandtotalpressureareconstants,BN+Si3N4phaseexistsatahighpartialpressureofNH3;(c)Theeffectoftotalsystempressureiscorrelatedtodepositiontemperature.Thetemperaturerangingfrom700to900℃underlowtotalpressureistheoptimumconditionforthedeposition.(d)Appropriatekineticparameterscanbedeterminedbasedontheresultsofthermodynamiccalculation.Si–B–Ncoatingisobtainedvialowpressurechemicalvapordeposition.TheanalysisbyX-rayphotoelectronspectroscopyindicatesthatB–NandSi–Narethemainchemicalbondsofthecoating.
简介:通过溶胶凝胶-熔盐法以NaCl为熔盐制备了掺杂Co^2+的Cd1-xCoxFe2O4(x=0~0.5)尖晶石型铁氧体。利用XRD、SEM和VSM等手段对样品进行了结构、形貌和磁性表征,并详细讨论了Co^2+对Co1-xCdxFe2O4(x=0-0.5)铁氧体结构和磁性的影响。结果表明:在研究范围内掺杂后仍然能得到单相尖晶石结构铁氧体;样品均为正八面体;比饱和磁化强度随x的增大而增加。
简介:Bismuth-basedSillen-Aurivilliuscompoundsarebeingexploredasefficientphotocatalystmaterialsforthedegradationoforganicpollutantsduetotheiruniquelayeredstructurethatfavourseffectiveseparationofelectron-holepairs.Inthiswork,wesynthesizedSillen-Aurivillius-relatedBi2YO4CIwiththebandgapof2.5eVbyasimplesolid-statereactionandsensitizedwithrhodiumnickel(RhNi)nanoparticles(NPs)toformtheRhNi/Bi2YO4CIheterostructure.PhotocatalyticactivitiesofBiOCI,Bi2YO4CIandtheRhNi/Bi2YO4CIheterostructurewereexaminedforthedegradationofrhodamine-6Gundervisible-lightillumination.ResultsdemonstratedthatthephotocatalyticdyedegradationefficiencyofRhNi/Bi2YO4CIheterostructuresishigherthanthoseofBiOCIandBi2YO4CI,attributedtothesynergisticmolecular-scalealloyingeffectofbimetallicRhNiNPs.Theplausiblemechanismforthedegradationofrhodamine-6Gandtheeffectiveelectron-holepairutilizationmechanismwerediscussed.