Preparation And Properties Of Indium Oxide And Tin Oxide Nano Powders By Electrolysis

Indium oxide and tin oxide as N-type semiconductors have various advantages due to their wide band gap,such as high thermal conductivity,excellent thermal stability,and high visible light transmission,etc.Indium oxide and tin oxide are widely used in the field of optoelectronic materials due to their excellent properties such as high activity and visible light transmission,These two oxide semiconductors are often used as raw material powders for ITO（Indium-Tin-Oxide）targets to prepare various optical display devices,In recent years,the development of large size,high resolution,flexible display devices,for ITO target performance put forward higher requirements.Traditional ITO powder preparation using the vapor phase method or co-precipitation method,due to indium ions and tin ions in the precipitation or gas phase parameters are not the same,using the same precipitation or gas phase parameters,it is difficult to control the consistency and coordination of the powder,and the preparation of a single grain size powder will lead to the target sintering densification process is difficult,but also difficult to adjust the proportion of SnO₂ doping in real time according to the actual situation,After a long period of storage and transportation,the prepared ITO targets are prone to grain boundary segregation after a long period of high temperature calcination,resulting in the generation of tin-rich or tin-poor phases,which affects the coating performance.Obtaining high quality In₂O₃ and SnO₂ monomer powder is an important basis for the preparation of high quality ITO targets.In this study,In₂O₃ and SnO₂ Nano powders were obtained by calcination after the preparation of precursors by electrolysis.It has the advantages of simple equipment,easy control of reaction,low production cost,high utilization rate,and friendly to the environment.Thermodynamic analysis of precursors by TG-DSC,characterization and determination of phase composition,morphology,particle size distribution and specific surface area of precursors and final products by XRD,SEM,TEM and BET.To provide theoretical guidance for the preparation of powders with single crystal shape,good microscopic morphology,uniform grain size and good crystallinity,The main research work and results are as follows:1、When preparing In₂O₃ powder by electrolysis,this paper studies in detail the effects of current density,electrolyte concentration,electric field shape,electrolysis temperature and sonication conditions,electrolyte p H,annealing temperature on the product.It was concluded that In（OH）₃ precursors were synthesized in a toroidal electric field apparatus with a current density of 0.25 A/cm²,electrolyte concentration of 1 mol/L and p H=7 under low temperature ultrasound conditions,Highly reactive In₂O₃ nanoparticles with a specific surface area of 18.41 m²/g and an average grain size of 62.69 nm with near spherical shape,high dispersion and good homogeneity were prepared by annealing at 500℃for 3 h.It is advantageous to optimize the relative density and resistivity of the subsequent ITO targets.2、When preparing SnO₂ powder by electrolysis,the effects of current density,electrolyte concentration,electrolysis temperature and ultrasonic conditions,and annealing temperature on the product are studied in detail.It was concluded that SnO and Sn₆O₄（OH）₄precursors with monolithic lamellar structures composed of multi-particle stacks were synthesized in a toroidal electric field apparatus with a current density of 0.2 A/cm² and an electrolyte concentration of 0.5 mol/L under low-temperature ultrasonic conditions,Solid subspherical SnO₂ nanoparticles with a specific surface area of 12.62 m²/g and an average particle size of 32.81 nm with good dispersion and homogeneity were prepared after annealing at 600℃for 3 h.3、In₂O₃ and SnO₂ were mixed with commercial vapor phase In₂O₃ and SnO₂ powders in a 9:1 mass ratio,ground and granulated,and then molded and sintered to prepare ITO targets.The relative densities of the obtained ITO targets were 93.67%and 84.18%,and the resistivities were 0.431 mΩ·cm and 5.010 mΩ·cm,respectively.SnO₂ particles with different grain sizes of In₂O₃ and 32.81 nm prepared using electrolytic method,According to the 62.69nm（5）32.81 nm,146.65 nm（5）32.81 nm,146.65 nm（5）62.69 nm（5）32.81 nm spherical stacking models,the relative densities were prepared as 93.67%,95.89%,94.56%,and resistivities of 0.431 mΩ·cm,0.374 mΩ·cm,0.410 mΩ·cm.The relative density and resistivity of ITO targets are also investigated at different sintering temperatures.