Synthesis and sintering of indium tin oxide nanoparticles by citrate-nitrate combustion method

Spherical indium tin oxide(ITO) nanoparticles were synthesized by combustion method using citric acid as fuel and nitrates as oxidizer.The obtained ITO nanoparticles were characterized by TG-DSC,FT-IR,XRD,BET,TEM,and SEM.The ITO nanoparticles grew steadily with the increase of heat treatment temperature,and the 700℃ calcined particles had a crystallite size of 25.3 nm and a specific surface area of 26.1 m2·g-1.The avoidance of chlorine ions in the synthesis process decreases particle agglomeration and promotes powder densification.The 900℃ sintered pellet had a density of 67.6% of theoretical density(TD) and increased steadily to 97.3% for the 1400℃ sintered ceramics,respectively.     

Facile synthesis of tin oxide nanocrystals and their photocatalytic activity

Tin oxide nanocrystals with diameters smaller than 10 nm were synthesized using Na₂SnO₃ and CO₂ as reactants and cetyltrimethylammonium bromide (CTAB) as stabilizer under mild conditions. As a mild acidic gas, CO₂ is favorable for the accurate adjustment of pH value of Na₂SnO₃ solution. Stannate salt is stable, cheap and easy in operation. The effects of Na₂SnO₃ concentration, CTAB concentration, aging temperature, and aging time on the nanocrystals were studied. It was found that, with the increasing Na₂SnO₃ concentration, aging temperature and aging time, SnO₂ nanocrystals size decreases. The formation of SnO₂ nanocrystals can be interpreted by electrostatic-interaction mechanism. SnO₂ nanocrystals show high photocatalytic activities in the degradation of Rhodamine B solution. The catalytic activity of small nanocrystals is higher than that of large ones.     

Preparation of silver tin oxide powders by hydrothermal reduction and crystallization

Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn（OH）4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag＋ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction （XRD） analysis,scanning electron microscope （SEM）,and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.     

Photoluminescence properties of hexagonal indium tin oxide nanopowders prepared by solvothermal method

Hexagonal structure indium tin oxide(ITO)nanopowders were prepared by a solvothermal process at only 175 ℃ for 24 h and post-annealing at 400 ℃, using metal indium and SnCl_4·5 H_2 O as the raw materials. The morphology, crystal structures and structure defects of products were, respectively, analyzed by scanning electron microscopy(SEM), X-ray diffraction(XRD) and confocal microprobe Raman system, the elemental state was investigated by X-ray photoelectron spectroscopy(XPS), and the optical properties were carried out by ultraviolet-visible(UV-Vis) and photoluminescence(PL) spectrophotometers. The results show that the products are hexagonal structure with a particles size of 28-41 nm; the morphology of products consists of sphere and irregular cubic.When pH values of solution increase, the content of oxygen vacancies increases and the optical band gap varies from3.59 to 3.78 eV. The products exhibit strong emission at417 nm with an excitation of 370 nm, and the PL intensity of samples increases with pH values increasing. Contrasting to cubic structure ITO powder, the hexagonal structure ITO has narrower optical band gap and higher PL intensity under the same excitation wavelength.     

Effect of Sn~(4+) content on properties of indium tin oxide nanopowders

Indium tin oxide(ITO)nanopowders were prepared by a modified chemical co-precipitation process.The influence of different SnO2 contents on the decomposition behavior of ITO precursors,and on the phase and morphology of ITO precursors and ITO nanopowders were studied by X-ray diffractometry,transmission electron microscopy and differential thermal and thermogravimetry analysis methods.The TG-DSC curves show that the decomposition process of precursor precipitation is completed when the temperature is close to 600 ℃and the end temperature of decompositionis somewhat lower when the doping amount of SnO2 is increased.The XRD patterns indicate that the solubility limit of Sn4+ relates directly to the calcining temperature. When being calcined at 700℃,a single phase ITO powder with 15%SnO2(mass fraction)can be obtained.But,when the calcining temperature is higher than 800℃,the phase of SnO2 will appear in ITO nanopowders which contain more than 10%SnO2.The particle size of the ITO nanopowders is 15-25 nm.The ITO nanoparticles without Sn have a spherical shape,but their morphology moves towards an irregular shape when being doped with Sn4+.     

Preparation of highly dispersed antimony-doped tin oxide nanopowders by azeotropic drying with isoamyl acetate

Antimony-doped tin hydroxide colloid precipitates were prepared by hydrolysis of SnCl4·5H2O and SbCl3 ethanol solutions. Isoamyl acetate was selected as azeotropic drying solvent and was compared with the most commonly used n-butanol solvent on treating precipitate for low hard agglomeration precursor powders. The FT-IR, BET, XRD, and TEM results of the precursor powders and calcinated antimony-doped tin oxide powders were recorded. The results demonstrate that isoamyl acetate is an excellent azeotropic drying solvent that can effectively prevent the agglomeration of particles and greatly improve the fluffiness of the obtained dried powders. After these precursor powders are calcined, antimony-doped tin oxide nanopowders with tetragonal futile structure and high dispersivity can be obtained.     

Surface modification of indium tin oxide films with Au ions implantation: Characterization and application in bioelectrochemistry

Indium tin oxide (ITO) thin film coated glass substrates have been implanted with 21 keV Au ions at a fluence of 1.0 × 10¹⁷ ions/cm² at room temperature. The resulting gold film was characterized with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectra and electrochemical methods. The results reveal that the implanted Au atoms were in the zero-valent metallic state and these Au atoms precipitated to form nanoclusters on the ITO surface whose average radius was estimated between 2 and 5 nm. The preferentially growing orientation was Au (111) plane during the formation process of gold film and the value of gold active surface area normalized by the geometric electrode areas was 0.48 for Au ion implanted ITO (Au/ITO) electrode. The potential utility of Au/ITO films was investigated. The Au/ITO electrode exhibited effective catalytic responses towards biomolecules such as ascorbic acid (AA) oxidation and lowered oxidation potential of AA by 0.6 V when compared with the bare ITO electrode. Myoglobin (Mb) was also successfully immobilized on the Au/ITO electrode and the direct electron transfer between proteins and electrode surface was realized. It was demonstrated that the Au/ITO film offered a favorable microenvironment for the orientation of biomolecules. New biomaterials with specific electrocatalytic and electrochemical features could be fabricated using this method.     

The characteristics of indium tin oxide films prepared on various buffer layer-coated polymer substrates

The optoelectronic and mechanical properties of flexible indium tin oxide (ITO) films are critical to the development of flexible optoelectronic devices. To improve the characteristics of the flexible films, the effects of inorganic buffer layers on the optoelectronic and mechanical characteristics of flexible ITO films prepared by ion-beam assisted deposition at room temperature were investigated. The results show that four inorganic buffer materials: SiO₂, Ta₂O₅, Al₂O₃ and TiO₂, have different effects on the optical transmission, sheet resistance and mechanical properties of ITO films. Ta₂O₅ buffer layer induces the highest optical transmission. SiO₂ buffer layer leads to the lowest sheet resistance. TiO₂ buffer layer reveals the most superior electrical stability against bending, which is attributed to the low thermal stress in ITO film.     

Effect of antimony doped tin oxide on behaviors of waterborne polyurethane acrylate nanocomposite coatings

A multi-functional waterborne polyurethane acrylate (WPUA) nanocomposite coating was prepared through introducing the acrylate groups into the end of the polyurethane main chains and then modified by antimony doped tin oxide (ATO) nanoparticles by ultrasonic dispersion. Structural and morphological features of coatings were assessed using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and a 3D measuring laser microscope. Performance of the coatings was evaluated using water resistance studies, thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA) and mechanical tests such as tensile strength, elongation at break. The data showed that the WPUA/ATO coatings possessed good mechanical properties and thermal stability. The UV-visible-near infrared (UV-VIS-NIR) spectra results suggested that the WPUA/ATO coatings could absorb near infrared radiation so that it would prevent heat transmission and heat diffusion effectively.     

锡铬铁生产工艺及其特点

介绍了锡铬铁产品的优点,其既有镀铬板附着力强、印涂性能好的优点,又有镀锡板可焊性好的优点,不必考虑镀锡板的熔锡问题,可采用较高的烘烤温度,提高印涂生产效率。针对目前我国锡铬铁生产处于刚起步阶段,介绍了锡铬铁生产工艺流程、预处理工艺和电镀工艺特点。     

Preparation of indium tin oxide targets with a high density and single phase structure by normal pressure sintering process

The present work mainly describes the technology for preparing indium-tin oxide (ITO) targets by cold isostatic pressing (CIP) and normal pressure sintering process.ITO powders were produced by chemical co-precipitation and shaped into an ITO green compact with a relative density of 60% by CIP under 300 MPa.Then,an ITO target with a relative density larger than 99.6% was obtained by sintering this green compact at 1550 ℃ for 8 h.The effects of forming pressure,sintering temperature and sintering time on the...     

电迁移诱发镀层锡须生长行为分析

分析了0.3×104 A/cm2恒定电流密度和四种不同加载时间（0,48,144和240 h）电迁移条件对6.5 μm厚镀锡层表面锡须生长行为的影响,以及不同电流密度对阴极裂纹宽度的影响.结果表明,电迁移加速了镀层表面锡须的形成与生长,随着电迁移时间的延长,锡须长度不断增加.此外,电迁移导致在阴极首先出现了圆形空洞,随后在两极均形成了圆形空洞,并且在阴极处还发现有微裂纹存在,随着电流密度增加,阴极裂纹宽度也随之增加,电流密度为0.5×104 A/cm2时,平均最大裂纹宽度约为9.2 μm.     

银氧化锡合金废料电解综合回收工艺研究

采用直流电解法和化学法回收银氧化锡(AgSnO2)合金废料中的银和锡。优化得到的电解银工艺参数为:槽电压1.5~3.0 V,电解周期为24 h,电解液中Ag⁺浓度为150~260 g/L,HNO3浓度为15~20 g/L,同极距120~140 mm,极板排布为六阴极五阳极间隔交替排列。一个周期银氧化锡废料电解银直收率接近95%,主体纯银粉在阴极析出。富含氧化锡的阳极泥和残极用硝酸浸出少量残余银,不溶渣还原熔炼回收锡,硝酸浸出的含银溶液中加入氢氧化钠调节pH值到10,沉淀得氧化银,500℃焙烧得到单质银。废料中的银和锡均得到有效回收。全流程银的回收率不低于99%。     

外加载荷对镀锡层锡须生长行为的影响

首先研究了三种不同厚度镀锡层（3,5,13 μm）在相同试验条件（70℃时效24 h后室温放置60天）下的锡须生长情况,并在此基础上首次采用精密动态力学分析仪（DMA Q800）研究了精确控制相同载荷条件下拉、压两种外力对相同厚度镀锡层（3 μm）锡须生长行为的影响.结果表明,相同时效条件下,镀锡层越薄,锡须生长的可能性越大;相同的外加载荷和试验温度作用下,承受压力作用镀锡层,其表面锡须生长比承受拉力时生长更快,并且主要呈柱状生长.     

配合-共沉淀法制备锑掺杂二氧化锡(ATO)粉

在充分回收含锡阳极泥有价金属的基础上,采用从锡锑二次资源中直接提取的高纯氯锡酸铵和氯氧锑为原料,合成了性能优良的纳米级锑掺杂二氧化锡(ATO)粉.针对液相共沉淀法制备ATO的过程中,锡和锑的水解不同步从而未能实现真正共沉淀掺杂的问题,以(NH4)2SnCl6和Sb4O5Cl2为原料,采用配合-共沉淀法,考察了反应过程中的pH、反应温度、掺锑浓度、煅烧温度、前驱体洗涤次数和分散剂种类等对ATO粒度和形貌的影响,确定了最优化条件,即:滴定终点pH=3,反应温度60℃,锑掺杂浓度10%(质量分数),热处理温度600℃,前驱体洗涤次数为6次,采用分散剂c,并进行了实验验证.     

Preparation of antimony-doped nanoparticles by hydrothermal method

Antimony-doped tin oxide (ATO) nanoparticles were prepared by the mild hydrothermal method at 200℃ using sodium stannate, antimony oxide, sodium hydroxide and sulfuric acid as the starting materials. The doped powders were examined by differential thermal analysis(DTA), X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The doping levels of antimony were determined by volumetric method and iodimetry.The results show that antimony is incorporated into the crystal lattice of tin oxide and the doping levels of antimony in the resulting powders are 2.4%, 4.3%and 5.1%(molar fraction). The mean particle size of ATO nanoparticles is in the range of 25 - 30 nm. The effects of antimony doping level on the crystalline size and crystallinity were also discussed.     

Effects of sulfur upon Fe and Cr oxide thermal stability in 304 stainless steel

X-ray photoelectron spectroscopy measurements show that exposure of an Fe–Cr–Ni alloy to H₂S and O₂ under ultrahigh vacuum (UHV) conditions leads to the thermal instability of the Fe oxide without affecting the Cr oxide. An atomically clean metal surface, predominantly Fe in composition and free of internal sulfur, was exposed to H₂S under controlled conditions in order to form a sulfided monolayer. Adsorbed S inhibited surface oxidation at temperatures between 325 K and 825 K. The presence of adsorbed S did not, however, inhibit the surface segregation of Cr for temperatures >600 K, compared to a S-free sample. Upon annealing of a sulfided sample to 900 K in UHV, the Fe oxide largely disappears, while no change is observed in the Cr oxide. The S-free sample shows no significant change in either the Fe or Cr oxides upon annealing. The results presented in this paper show that sulfidation of an alloy surface prior to oxidation and surface segregation can adversely affect the thermal stability of the Fe oxide without affecting the Cr oxide overlayer resulting from surface segregation and preferential oxidation.