Preparations And Characterizations Of NiO Nano-wires And ATO Nano-powders

NiO Nano-powders have been used in such areas as catalyst,electrode,gas sensors and magnetic materials.Preparation and applications of NiO Nano-powders are reviewed anywhere.There are a wide variety of preparation solutions of NiO Nano-powders.Therefore,it is important to choose a preparation solution which has such advantages as simple techniques,low cost and easy to be industrialized and scientific parameters.The author carries out an experiment to prepare NiO Nano-powders containing different nickel salts and precipitation agents via liquid chemical precipitation.Antimony-doped tin oxide(ATO)is an important member of transparent conductive oxides.The preparation and application of the nanometer transparent and conductive materials was paid more attention in the abroad,especially American and Japan.However in our country it mainly depends on the imported product.This experiment's target is improve the product' characters,and take place of the imported product.ATO particles have been synthesized by solid-state reaction, co-precipitation and hydrothermal methods.The major disadvantages of these preparation methods are larger particle size,impurity induction and high cost.In this paper,it is significance for exploring a new preparation of conductive ATO nanoparticles.1.The NiCl₂·6H₂O and NiSO₄·6H₂O were chosen as nickel salts, Na₂CO₃,NaOH,NH₃·H₂O and H₂C₂O₄·2H₂O as precipitation agents,preparing different topography NiO Nano-powders via single phase precipitation.The precursor has been detected by DSC/TG.The structure,particle sizes and topography of NiO powders were investigated by means of XRD and SEM.The results of the DSC/TG show that the precursor was completely decomposed under 400℃.The results of the XRD show that NiO Nano-powders were cube crystal structure.The diffraction peaks were in 37.3°,43.3°and 62.9°,which were consistent with normal pattern.The results of the SEM show that the way comes out first we choose NiSO₄ as nickel salt,NH₃·H₂O and H₂C₂O₄·2H₂O as precipitation agents via single phase precipitation.The optimum parameters were determined in this system as:pH values of solution 8.4,reaction temperature 60℃,concentration of Ni²⁺0.8mol/L,roasting temperature 400℃.The length-radius proportion of nickel oxide nanowire prepared is greater than 20 under optimum conditions.2.Antimony-doped tin oxide(ATO)nanoparticles were prepared by alkoxide hydrolysis method using SnCl₄·5H₂O and SbCl₃ as starting materials.The optimum parameters are determined as:Sb⁵⁺doped concentration(mol%)15%,titration end point pH values 2,reaction temperature 60℃,heat treatment temperature 600℃. Under this conditons,the obtained particles were characterized by means of XRD and TEM.X-ray diffraction shows that all Sb ions came into the SnO₂ lattice to substitute Sn ions.TEM shows the ATO nanoparticles average sizes were 5 nm. Volume resistivity lowest values of ATO powders were 141Ω·cm.