氧化铑电致变色薄膜的制备、结构及性能

采用溶胶_凝胶方法在ITO导电基底上制备氧化铑电致变色薄膜 .当在碱性溶液中对薄膜分别施加阴极和阳极电位时 ,薄膜即呈现由亮黄到深绿的可逆变化 .采用原位XRD、TG_DTA、IR、XPS等方法对薄膜的结晶态、热处理过程以及膜的化学组成进行分析 .应用交流阻抗法计算了薄膜变色过程的扩散系数 ,结果表明该膜基本可以用于变色器件     

Electrochemical and Electrochromic Properties of Ni Oxide Thin Films Prepared by a Sol–Gel Method

Nickel oxide thin films, which are well known anodic coloration materials that are used in electrochromic devices, were prepared by a sol–gel method, and their electrochemical and electrochromic properties were investigated. The sol was prepared from Ni(OH)₂ powder with an average size of 7 nm, in a mixture of ethylene glycol and absolute ethanol. The films were coated on an ITO substrate using the powder, dispersed in the solution. When additive materials, acetyl acetone and glycerol, were added to the sol its hardness and adhesion properties were improved. The optimized thin film formed an amorphous, porous structure, and showed a large current density during continuous potential and pulse potential cycling. The film also was transparent and had a high coloration efficiency (33.5 cm²/C) and a rapid response time (1.0–2.5 s) during the coloring/bleaching process.     

脉冲激光沉积制备氧化铋薄膜的电致变色性质

通过电位阶跃和循环伏安结合现场电感偶合分光光度计(CCD)测量了脉冲激光沉积的四方结构Bi2O3薄膜的电致变色性质. 结果表明, 在波长为630 nm处出现一个明显的吸收峰, Bi2O3薄膜电极的着色时间为30 s. 吸光度-电位谱图表明, 当电位在3.5 - 0.7 V之间变化时, Bi2O3薄膜的颜色可明显地呈现由透明到暗棕色的可逆变化, 重复次数可达50 次, 在630 nm测得的着色效率约为15 cm2·C-1.     

氧化铑变色薄膜的制备及其电变色研究

采用溶胶-凝胶方法制备了氧化铑电致变色薄膜。通过施加阴极或阳极电位, 薄膜在碱性电解液中呈现从亮黄（还原态）到深绿（氧化态）的可塑颜色变化,而 且可达到上千次循环而性能不变。采用XRD,SEM,TG,DTA,UVV,FTIR和循环伏安 等技术对薄膜的晶态、形貌、热处理过程和电变色过程进行了研究。得出100 ℃处 理的膜内含有一定量的结晶水,其性能最好。对薄膜的电致变色性能如：着色效率 、响应时间及循环寿命、开路记忆等进行了测试,并讨论了氧化铑薄膜电变色的反 应机理。     

溶胶-凝胶法制备钯催化剂的织构与性能

采用溶胶-凝胶法制备了Pd/Al2O3催化剂，用LLS(激光光散射)、XRD和BET等技术考察了溶液pH值对所成胶体粒子流体力学半径、相应催化剂产品孔径分布及热稳定性的影响.研究发现，由pH=4.1的胶体制备的催化剂具有良好的热稳定性和CO、C3H6的氧化活性.氧化镧添加剂可抑制Al2O3载体在高温下由γ相向α相的转化，同时也促进了催化剂上Pd粒子的生长. La2O3可提高新鲜Pd催化剂的氧化活性，但对老化后催化剂活性的提高无促进作用.     

Sol-gel法制备La1-xSrxMnO3巨磁电阻薄膜材料

利用sol-gel法在单晶硅Si(100)衬底上,制备了钙钛矿La_1-xSr_xMnO₃(LSMO)低织构纳米晶薄膜.考察了制备条件对LSMO成相、晶粒的粒度和表面形貌的影响,研究了其磁特性和磁电阻性能.结果表明,La_0.7Sr_0.3MnO₃薄膜磁电阻效应在相当宽的温度范围内不随温度改变,在6T磁场中室温下磁电阻比MR值可达-30%.     

An Efficient Route to Nanostructured Tungsten Oxide Films with Improved Electrochromic Properties

An effective chemical route to nanostructured tungsten oxide films derived from a peroxopolytungstic acid (PTA)/thiourea precursor solution is demonstrated. The conventional procedure of preparing the precursor needs more than 24 h for well‐mixing and refluxing the PTA‐based solution, while the thiourea‐assisted approach takes less than 1 h to prepare the precursor solution because the excess hydrogen peroxide can be efficiently eliminated by oxidation of thiourea. With the precursor solution, tungsten oxide films are deposited by spin coating followed by high temperature annealing. The film annealed at 400 °C possesses a porous nanostructure of nanocrystalline tungsten oxide embedded in an amorphous tungsten oxide matrix, which arises from the gaseous species released through decomposition of thiourea oxides during annealing. The 400 °C‐annealed, thiourea‐assisted tungsten oxide film exhibits electrochromic (EC) properties superior to those of the film prepared without thiourea, including large transmittance modulation and coloration efficiency, fast response time and adequate reliability. When increasing the annealing temperature to 450 °C, the thiourea‐assisted tungsten oxide film is also porous but well‐crystallized and shows inferior EC properties. Electrochemical impedance spectroscopy analysis indicates that, in addition to the porous structure, a fast charge‐transport rate within the solid portion of the 400 °C‐annealed nanostructured film plays a crucial role in enhancing EC performances of the thiourea‐assisted tungsten oxide film.     

ZnO纳米棒薄膜的湿化学法制备及光致发光特性

在80 ℃水浴下, 采用简易的湿化学法在不导电玻璃基底上制备了ZnO纳米棒阵列, 利用X射线衍射仪(XRD)和场发射扫描电镜(FE-SEM)对样品的结构形貌进行了表征. 结果表明, 晶化30 min所得产物为六方纤锌矿相的ZnO纳米棒, 直径大约为80~90 nm. 为了分析不同的低温退火温度和退火气氛对其光致发光性能的影响, 研究了ZnO纳米棒薄膜在不同的后处理条件下的光致发光谱(PL). 实验结果表明, 在O₂气氛下于450 ℃退火1 h后, ZnO纳米棒薄膜的红光发射(约650 nm)强度相对在空气和5%H₂/95%N₂气氛下退火的样品变得更强, 而且该样品的激发波长范围(200~370 nm)与近紫外发光二极管(LEDs)的发射波长范围(350~420 nm)匹配得很好.     

溶胶-凝胶法制备的MgxZn1-xO纳米薄膜结构和光学性质

用溶胶-凝胶法制备了不同组分的Mg_xZn_1-xO薄膜.X射线衍射结果表明,薄膜为具有六角纤锌矿结构的纳米薄膜,晶粒尺寸3～5nm,随着Mg进入ZnO晶格,其晶格常数变小.紫外-可见吸收光谱表明,随着Mg含量的增加带隙变宽,自由激子吸收峰明显蓝移.室温光致发光光谱由很强的且与氧空位相关的深能级缺陷发光和较弱的紫外激子发光组成,激子发光强度和缺陷发光强度比随x的增大而减小,表明Mg原子进入ZnO晶格会引起深能级缺陷的增加.Mg_0.03Zn_0.97O薄膜经700℃热氧化后,紫外与可见发光强度比达到30.     

Effect of Doped Boron on the Properties of ZnO Thin Films Prepared by Sol-gel Spin Coating

Transparent conductive boron-doped ZnO thin films were prepared by sol-gel spin coating method. The effect of doped boron concentration on the properties of the films was systematically discussed. The films were characterized by X-ray diffraction, atomic force microscopy, spectrophotometry, and Hall effect measurement system. All the doped and undoped ZnO films were of a single hexagonal structure, and showed a preferred orientation of （002）. The particle size and surface roughness of the films decreased with increased doped boron concentration. All the films exhibited an average transmittance of approximate 90% in visible-light region and an energy gap of about 3.3 cV. The maximum carrier concentration, the highest carrier mobility and the lowest resistivity were observed at a doped boron concentration of 0.5%（molar fraction）. Based on these results, we suggested that the saturation concentration of doped boron in ZnO film is 0.5%（molar fraction）.     

苯胺四聚体薄膜的制备及其电致变色性能

以苯胺四聚体做为电致变色材料, 在保持ITO有效涂覆面积不变的情况下, 通过控制溶液浓度和用量的方式控制膜厚, 采用自然铺展的方式制备得到了均匀的电致变色膜. 循环伏安特性曲线表明, 在－0.2～0.8 V电压范围内, 随着电压的升高, 苯胺四聚体结构发生从还原态到中间态再到氧化态的转变, 并伴随着颜色从浅黄色到绿色再到蓝色的变化. 研究发现, 电解质溶液种类和膜厚对苯胺四聚体膜的电致变色性能有较大影响. 苯胺四聚体膜的对比度按照HCl, HNO₃, H₂SO₄, LiClO₄电解质溶液的顺序依次降低. 随着膜厚度增加, 苯胺四聚体膜的对比度增加, 响应时间延长. 当采用樟脑磺酸掺杂的苯胺四聚体制备电致变色膜时, 在其他条件相同的情况下可以提高苯胺四聚体膜的对比度并同时缩短响应时间.     

Sol-Gel Derived Hydrated Nickel Oxide Electrochromic Films: Optical, Spectroelectrochemical and Structural Properties

Electrochromic hydrated Ni-oxide films were prepared using a dip-coating technique from a nickel sulphate heptahydrate precursor in combination with glycerol, formamide and polyvinyalcohol. In-situ monochromatic (λ=400 nm) spectroelectrochemical measurements using a potential of −0.4 V to 0.8 V in 0.1M LiOH electrolyte revealed that the electrochromic efficiency was 23.5 cm²/C. The observed colouring/bleaching transmittance of a 100 nm thick film changed during potential cycling (20 cycles) by 45%. Ex-situ FT-IR absorption/reflection measurements performed at near-grazing incidence angle conditions (80°) confirmed transformation of as-deposited α-Ni(OH)₂ phase to β-Ni(OH)₂ at cathodic (bleached state) and β-NiOOH at anodic (coloured state) potentials during extended cycling (200 cycles). Clear evidence of the OH⁻ ions insertion and release of SO ₄ ²⁻ ions from the as-deposited films when soaked (0.5 hour) in 0.1M LiOH are given. These processes are accompanied by the transformation of the residual COO⁻ groups originating from the peptisation with glacial acetic acid into CO ₃ ²⁻ species residing in the films during extensive potential cycling.     

Electrochromic Properties of Peroxopolytungstic Acid Thin Films

Electrochromic thin films have been deposited from peroxopolytungstic acid aqueous solutions. These solutions are obtained via the dissolution of tungstic acid in hydrogen peroxide. The nature and properties of the films depend on the drying procedure. Amorphous films are formed upon fast drying. They exhibit good electrochromic properties but have to be heat treated in order to become insoluble. Crystalline films are formed upon slow drying. Their electrochromic properties are not very good but better amorphous or crystalline films are then obtained after a thermal treatment above 200°C. In both cases, the reversibility of lithium insertion is not good during the first cycles but improve significantly upon cycling. This should be due to the electrochemical reduction of peroxo groups.     

超细氢氧化亚镍的溶胶凝胶法制备及其准电容特性

以聚乙二醇为抑制剂,采用溶胶凝胶法制备了粒径小于200 nm且具有链珠状特殊形态的超细氢氧化亚镍电极材料.伏安特性测试和电化学阻抗测试表明在氢氧化亚镍中掺加适量碳纳米管可以显著改善电极材料的容量特性和阻抗特性,其中碳纳米管质量分数为20％的复合电极其比电容量可以达到320 F&;#8226;g^－1.采用复合电极作为正极,活性炭电极作为负极组成的复合型电化学电容器最大工作电压可以达到1.6 V,具有良好的容量特性和大电流放电特性.恒流充放电测试证明复合型电化学电容器具有高能量密度及高功率放电特性,电容器的峰值功率密度为8.6 W&;#8226;g^－1.当以0.88 W&;#8226;g^－1功率放电时,电容器能量密度可达20.11 W&;#8226;h&;#8226;kg^－1, 当采用3.46 W&;#8226;g^－1的高功率进行放电时,复合型电容器的能量密度仍然能够达到11.11 W&;#8226;h&;#8226;kg^－1.     

MoO3电致变色薄膜的XPS研究

Molybdenum oxide films were fabricated successfully by spin coating from Li＋ doped peroxo polymolybdate solution via sol gel technique.Their electrochemical and electrochromic properties were investigated by cyclic voltammetry and in situ UV transmittance measurements.The results showed that the films possessed excellent electrochemical stability and reversibility.The electrochromic mechanism of the MoO3 was discussed by using results obtained from X ray photoelectron spectroscopy (XPS).The results showed that the most part of the Mo6＋ in MoO3 film was reduced to Mo5＋ and Mo4＋ ions during the Li＋ intercalation process,Mo4＋ was oxidized to Mo5＋ and part of Mo5＋ was oxidized to Mo6＋ again during the Li＋ deintercalation process.So it was considered that Mo4＋ ions existed in the colored MoO3 films.     

Structural and Electrochromic Properties of Co-Oxide and Co/Al/Si-Oxide Films Prepared by the Sol-Gel Dip Coating Technique

The sol-gel dip-coating technique was used for depositing cubic spinel Co₃O₄ and amorphous Co/Al/Si-oxide thin films. Both types of films exhibit similar electrochrochemical properties which are accompanied by the hydration of the structure. The electrochromic properties of Co/Al/Si-oxide surpass those already known for Co-oxide based electrochromic materials. The change in transmittance for spinel Co₃O₄ is 25%, while for Co/Al/Si-oxide films exceeds 50%. The electrochromic efficiency () for Co₃O₄ and Co/Al/Si-oxide films was 22 cm² C^-1, which is comparable to other electrochromic oxides. Good electrochromic properties of the Co/Al/Si-oxide films make them promising materials for active counter electrode in electrochromic devices.     

MoO_3电致变色薄膜的XPS研究

近年来 ,随着人们提倡节能和使用洁净能源 ,无机电致变色材料在建筑物采光控制系统和反射率可调表面的应用研究 ,已成为材料领域的一个新热点 .WO3、 MoO3等过渡金属氧化物薄膜具有良好的电致变色效应 ,是人们研究的重点 .其中 MoO3的电致变色效果要好于 IrO2、 TiOx、 CoO及 NiOx等电致变色材料 [1],而且它在可见光区有比 WO3更柔和的色彩 ,使人眼更易于适应其颜色变化 .着色态的 MoO3称为钼青铜 ,其开路记忆也好于钨青铜 [2].故 MoO3电致变色薄膜是极有潜力用于实用化的电致变色器件 .MoO3薄膜常用的制备方法有真空蒸 发、化学气…     

水辅助法制备聚醚酰亚胺微孔膜

通过水辅助法采用聚醚酰亚胺的氯仿溶液制备了聚醚酰亚胺微孔膜, 并研究了环境相对湿度和聚合物浓度对孔形貌的影响. 研究结果表明, 在优化条件下, 可以制备规则均一的聚醚酰亚胺(Ultem 1010)微孔膜, 而且微孔膜的热稳定性、耐腐蚀性以及力学性能表现优异.     

Third-Order Nonlinear Optical Properties and Dielectric Properties of Pb-Complex Perovskite Thin Films Prepared by Sol-Gel Method

The third-order nonlinear optical properties of the sol-gel derived Pb(Fe_1/2Nb_1/2)O₃-PbTiO₃ (PFN-PT) thin films have been investigated by the THG method. The χ⁽³⁾ values of PFN-PT thin films increased from 3.2×10⁻¹² esu (PT) to 8.5×10⁻¹² esu (PFN) with increasing content of Fe³⁺ ions which possessed very high second-hyperpolarizability, ψ(Fe_2/3O). It was experimentally confirmed that complex oxides such as ABO₃-type perovskites consisting of large non-transition metal A-site cations and small transition metal B-site cations exhibited high χ⁽³⁾ as expected from Lines' model. It was also found that the χ⁽³⁾ values of complex oxides could be estimated from the second-hyperpolarizabilities of the constituent single oxides reported so far. Because of the large remanent polarization, PT thin films may exhibit the highest χ⁽³⁾ among the ferroelectric PFN-PT thin films studied in the present work. The maximum dielectric constant, ε, of 1990 at room temperature was obtained for 0.5PFN·0.5PT thin films, whose composition corresponds to so-called morphotropic phase boundary (MPB).     

Metal Oxide Thin Films Containing Au Nano-Particles Prepared with Gas Diffusion Method

Au particles dispersed thin metal oxide films were prepared from precursor films containing HAuCl₄ with H₂S gas diffusion method. HAuCl₄ was uniformly dissolved in the films as promoted by hydroxypropyl cellulose (HPC). The mechanism of the Au particle formation was studied. It was found that HAuCl₄ was converted directly to Au metal particles upon contacting with H₂S gas. Au particles generated by this method were characterized with small particle size, sharp size distribution and high volume fraction in the films. The surface plasma resonance absorption of Au particles shifted to longer wavelength when TiO₂ component was introduced in the matrix.