ZrO2及ZrO2:CdS薄膜的制备和表征

利用ｓｏｌ－ｇｅｌ方法合成了ＺｒＯ_２薄膜,并通过在ＺｒＯ_２薄膜中复合ＣｄＳ纳米粒子成功地制备了ＺｒＯ_２：ＣｄＳ薄膜．制得的ＺｒＯ_２薄膜透明并具有较好的光透射性,而ＺｒＯ_２的含量及膜厚是影响其光透射性的主要因素．分散在ＺｒＯ_２：ＣｄＳ薄膜中的ＣｄＳ纳米粒子为六方相结构,并具有较好的分散性,其平均尺寸为４～６ｎｍ．实验结果表明：ＺｒＯ_２颗粒的晶化会对薄膜的光学性能及表面形貌产生影响,但ＣｄＳ的形成可以抑制薄膜表面ＺｒＯ_２颗粒的晶化,从而得到较为平滑的薄膜．     

TiCl4-O2体系高温反应制备超细TiO2光催化材料的研究

高温管式气溶胶反应器中,利用ＴｉＣｌ_４气相氧化制备超细ＴｉＯ_２光催化材料,研究了停留时间和反应温度对粒子形态的影响．结果表明ＴｉＯ_２粒度随停留时间延长和反应温度升高而增大;金红石相含量随停留时间延长而增加,当反应温度１３００℃时,粒子中金红石含量出现最大值．以偶氮染料活性艳红Ｘ－３Ｂ为模拟废水;考察粒子光催化活性．光催化活性与粒径和晶型等形态指标有关,等效粒径３６．４ｎｍ、金红石含量１８９７％ＴｉＯ_２的活性高于商品Ｐ２５和ＳＨ－１．     

共沉淀法制备钛酸钡微粉的研究

对以ＴｉＣｌ_４和ＢａＣｌ_２为原料,以ＮＨ_４ＨＣＯ^３＋ＮＨ_３·Ｈ_２Ｏ作沉淀剂,制备钛酸钡粉末的过程进行了详细的热力学分析,找出了合成钛酸钡的条件和范围,详细地讨论了反应方式和前躯体洗涤条件．实验研究了反应物钡钛比,终点ｐＨ值,煅烧温度,以及分散剂对产物理化性能的影响．结果表明：在ＮＨ_４ＨＣＯ_３／ＢａＣｌ_２＝１．２,ＴｉＣｌ_４／ＢａＣｌ_２＝１－１．０１,充分搅拌反应１ｈ,煅烧温度９２０℃,煅烧时间２ｈ条件下,可以制得较理想的产物．在反应体系中加入适量分散剂可以明显降低产物的粒径．     

煤矸石的纳米结构及其对合成SiC的影响

通过ＡＦＭ研究,发现硅质煤矸石的两种主要组成ＳｉＯ_２和Ｃ具有纳米粒状结构和纳米层状结构．ＳｉＯ_２纳米颗粒的尺度为３～２０ｎｍ,Ｃ质纳米颗粒的尺度为１０～２０ｎｍ．纳米层厚为５～８０ｎｍ．矸石中的ＳｉＯ_２和Ｃ呈密接触状态．用这种结构的煤矸石为原料,在１３００℃时就可合成β－ＳｉＣ,其合成温度明显低于人工混合物料同等条件下的合成温度,而且产率也可大幅度提高．     

嵌有纳米碳颗粒凝胶玻璃的制备及其发光特性

以磷酸三乙酯、硝酸铝和正硅酸乙酯为原料,通过它们的水解制备了ｘＡｌ_２Ｏ_３·ｘＰ_２Ｏ₅·１００ＳｉＯ_２（ｘ＝０．２５～３）凝胶．在６００℃对凝胶进行热处理,使其中的有机基团炭化,从而制备出了镶嵌有碳纳米颗粒的ｘＡｌ_２Ｏ_３·ｘＰ_２Ｏ_５·１００ＳｉＯ_２（ｘ＝０．２５,０．５）凝胶玻璃．在室温下以５３２ｎｍ激光（Ｎｄ：ＹＡＧ）激发,在 ６３０ｎｍ处有一强的发光峰,该发光现象是由镶嵌在凝胶玻璃中的纳米碳颗粒产生的．     

Li2MnO3的柠檬酸盐溶胶-凝胶法合成及离子导电性

以Ｌｉ_２ＣＯ_３、ＭｎＣＯ_３为原料,用柠檬酸盐溶胶凝胶法合成了Ｌｉ_２ＭｎＯ_３超微粉．对合成的材料进行了ＤＴＡ、ＴＧ、ＸＲＤ和ＴＥＭ等表征,并应用交流阻抗谱技术测定了样品的电导率．结果表明,６５０。Ｃ以上生成Ｌｉ_２ＭｎＯ_３纯相超微粉,粒径在５０nｍ以下．在１８～４００℃温度范围内,产物烧结体的离子导电率为１０^－６～１０^－３Ｓ·ｃｍ^－１,其电导活化能为４４．８７ｋＪ·ｍｏｌ^－１．     

原位氮化法制备纳米TiN-Al2O3复合粉体

以化学共沉淀法制备的纳米ＴｉＯ_２－Ａｌ_２Ｏ_３复合粉体为原料,采用原位选择性氮化的方法制备了纳米ＴｉＮ－Ａｌ_２Ｏ_３复合粉体．应用化学热力学原理分析、计算了氮化反应的条件和机理,研究了氮化条件对氮化反应的影响．实验结果表明,氮化反应在７００℃时开始进行,在９００℃保温５ｈ,氮化反应进行完全,ＴＥＭ照片显示纳米ＴｉＮ 颗粒均匀分布于Ａｌ_２Ｏ₃基体中,粒径为５０～７０ｕｍ．     

以正钛酸为原料制备纳米TiO2光催化剂

以正钛酸为原料,通过直接水解法制备纳米ＴｉＯ_２;并对样品分别进行了差热分析、Ｘ射线衍射分析和透射电子显微镜分析．结果表明,样品粒子为混晶型纳米ＴｉＯ_２,单分散性良好,粒径分布范围狭窄．当它应用于阴离子表面活性剂十二烷基苯磺酸钠的光催化降解时,与Ｐ－２５光催化剂相比,具有较好的催化活性．同时,我们用Ａｌ_２Ｏ_３陶瓷膜回收纳米ＴｉＯ_２循环再利用;这为纳米ＴｉＯ_２在环保方面的大规模应用创造了条件．     

表面诱导沉淀法制备Al2O3-ZrO2纳米复合粉体

采用表面诱导沉淀法,制备了Ａｌ_２Ｏ_３－ＺｒＯ_２（１５ｖｏｌ％）纳米复合粉料,利用透射电子显微镜对其形貌进行了表征．结果表明：在ｐＨ＝５时,可以使ＺｒＯ_２前驱体均匀地包裹在Ａｌ_２Ｏ_３颗粒表面,经过８００℃煅烧之后,Ａｌ_２Ｏ_３颗粒表面均匀地结合着粒径约为３０ｎｍ的ＺｒＯ_２颗粒,ＺｒＯ_２颗粒尺寸均匀．该粉体经过２４ｈ球磨和超声波处理之后,未发生ＺｒＯ_２颗粒脱落现象,表明ＺｒＯ_２颗粒与Ａｌ_２Ｏ_３颗粒表面结合紧密．     

卤化银多晶光纤传输CO2激光性能的研究

通过采用高真空熔炼、反应气氛下区域融熔和高真空石英安瓿内单晶生长等特殊工艺方法对卤化银原料进行提纯,并用热挤压成型方法制得卤化银光纤．本文研究了卤化银原料的提纯和光纤成型工艺对损耗的影响,研究结果表明,增加提纯次数可降低卤化银光纤预制棒的吸收系数．通过合理控制工艺参数,提纯后的卤化银原料制成的光纤预制棒,经ＣＯ_２激光量热计法测量在１０．６μｍ处的吸收系数＜５×１０^－4ｃｍ^－１,热挤压成型的光纤在１０．６μｍ处的损耗为０.３～０.５ｄＢ／ｍ,直径φ１０ｍｍ、长度１．６４ｍ的光纤可传输ＣＯ_２激光功率＞２０Ｗ．     

在酸性条件下采用高能球磨法制备 Cu2O纳米粉末

采用行星球磨机在pH=2的稀盐酸溶液中对Cu粉进行球磨，球磨机简体和磨球材质均为纯Cu，球料比为20：1，球磨机转速为300r／min，通过X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等对球磨产物进行了表征．XRD结果表明，球磨3h后，所加入的纯Cu粉末基本转化为Cu20粉末．球磨70h后得到纯的Cu20粉末，粉末粒度为50-100nm．并对Cu20纳米粉末的生成机制及球磨工艺参数对Cu20形成的影响进行了讨论．     

CuO Nanoplates for High‐Performance Potassium‐Ion Batteries

Potassium‐ion batteries (KIBs) are promising alternatives to lithium‐ion batteries because of the abundance and low cost of K. However, an important challenge faced by KIBs is the search for high‐capacity materials that can hold large‐diameter K ions. Herein, copper oxide (CuO) nanoplates are synthesized as high‐performance anode materials for KIBs. CuO nanoplates with a thickness of ≈20 nm afford a large electrode–electrolyte contact interface and short K⁺ ion diffusion distance. As a consequence, a reversible capacity of 342.5 mAh g^?1 is delivered by the as‐prepared CuO nanoplate electrode at 0.2 A g^?1. Even after 100 cycles at a high current density of 1.0 A g^?1, the capacity of the electrode remains over 206 mAh g^?1, which is among the best values for KIB anodes reported in the literature. Moreover, a conversion reaction occurs at the CuO anode. Cu nanoparticles form during the first potassiation process and reoxidize to Cu₂O during the depotassiation process. Thereafter, the conversion reaction proceeds between the as‐formed Cu₂O and Cu, yielding a reversible theoretical capacity of 374 mAh g^?1. Considering their low cost, easy preparation, and environmental benignity, CuO nanoplates are promising KIB anode materials.     

Controlled reduction of Cu to Cu with an N,O-type chelate under hydrothermal conditions to produce Cu2O nanoparticles

N,O-type organic chelates reduced coordinated Cu²⁺ ions under hydrothermal reaction conditions to produce Cu₂O/CuO nanoparticles. Chelates in which the N and O atoms are closely spaced produced smaller amounts of CuO nanoparticles, indicating their higher ability to reduce Cu²⁺ ions to Cu⁺ ions. [Cu(Gly)₂]² with the shortest ligand chain length produced only Cu₂O nanoparticles and, therefore, can be used as a single molecule precursor for the synthesis of Cu₂O nanoparticles.     

High-energy ball milling of intermetallic Ti-Cu alloys for the preparation of oxide nanoparticles

Copper and titanium oxides in the nano-size range show unique chemical and physical properties and thus have been intensively considered for novel and smart applications. In this work, oxide nanoparticles were prepared by high-energy ball milling of Ti-Cu alloys followed by a controlled oxidation process. Alloys of the Ti-Cu system Ti-50Cu, Ti-57Cu, and Ti-65Cu (in wt.%) prepared by arc melting were selected considering they provide different starting brittle intermetallic phases before milling. Microstructural investigation indicated that Ti-50Cu was composed of Ti₂Cu and TiCu, while Ti-57Cu was single-phase TiCu. Ti-65Cu was dual-phase and consisted of Ti₃Cu₄ and Ti₂Cu_3. A mean particle size below 10 nm was achieved after high-energy ball milling for all compositions. The oxidation process was then investigated in two temperature ranges. At high oxidation temperatures of 700–800 °C, a complete oxidation took place leading to oxides TiO₂-rutile and CuO in all alloys. However, at a low oxidation temperature (350 °C), partial oxidation occurred and different oxides were obtained. Ti-50Cu was the most promising alloy and led to a mix of TiO₂ (rutile and anatase), CuO, Cu₂O, and Ti₃Cu₃O. After long exposure to thermal oxidation, the resulting oxides remained in the nanometric range with a particle size distribution showing a D50 of approximately 6 nm.     

Synthesis of copper and copper(I) oxide nanoparticles by thermal decomposition of a new precursor

The present investigation reports, the novel synthesis of nanoparticles Cu and Cu₂O using thermal decomposition and its physicochemical characterization. The nanoparticles copper powder have been prepared using [Bis(salicylidiminato)copper(II)], [Cu(sal)₂], as precursor. Cu nanoparticles are initially formed and subsequently oxidized to form Cu₂O. Transmission electron microscopy (TEM) analysis demonstrated nanoparticles Cu₂O with an average diameter of about 10 nm. As-prepared copper nano-particles were characterized by X-ray diffraction measurements (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX), and Fourier transform infra-red spectroscopy (FTIR). XRD analysis revealed broad pattern for fcc crystal structure of copper metal and cubic cuprite structure for Cu₂O. Optical absorption measured by UV–visible spectroscopy was used to monitor oxidation course of Cu → Cu₂O and to determine the band-gap energy about 2.4 eV for Cu₂O nanoshells.     

Fabrication of CuO and Cu2O nanoparticles in a thick polyimide film by post heat treatment in a controlled-atmosphere

We investigated the formation of CuO or Cu2O nanoparticles in the thick polyimide films by oxidizing Cu nanoparticles at various temperatures during the post heat-treatment. Cu nanoparticles of 4-5 nm in diameter were initially formed in the polyimide film by the reaction between a Cu film and a polyimide precursor, polyamic acid, and a following thermal curing in a reducing atmosphere. After the subsequent post heat-treatments in oxidizing atmospheres, X-ray diffraction patterns revealed that initial metallic Cu nanoparticles were transformed to Cu2O or CuO nanoparticles depending on the temperature during the post heat-treatment. Cu nanoparticles were oxidized to Cu2O during the post heat-treatment at low temperature while Cu nanoparticles were oxidized to CuO during the post heat-treatment at high temperature. Cross-sectional TEM studies showed that about 4.7 nm sized Cu2O nanoparticles or 4.7-5.2 nm sized CuO nanoparticles were fabricated in a thick polyimide film depending on the post heat-treatment condition. In the optical absorption measurements, the absorption peak from surface plasmon resonance of Cu nanoparticles disappeared during the post heat-treatment in an oxidizing atmosphere.     

Oxidation behavior of copper nanoparticles at low temperature

A mass gain for copper nanoparticles with a mean diameter of 20 nm in a 20% oxygen-nitrogen atmosphere was measured at 150-300 °C using thermogravimetry (TG). The mass gain equilibrium of the copper particles differed at each temperature, and a threshold temperature was recorded. Oxide products, consisting mainly of Cu₂O, formed on the copper nanoparticles below the threshold temperature. Above the threshold temperature, there was an initial, and drastic, formation of Cu₂O, which then changed to CuO. The activation energy for the oxidation of the copper nanoparticles that could be calculated from the rate of the mass gain was an indication of the nano-effect of the copper nanoparticles.     

Mechanisms of carrier generation and transport in Ni-doped Cu2O

The density and mobility of hole carriers in Ni-doped and undoped cuprous oxide (Cu₂O) films prepared by pulsed laser deposition (PLD) from Ni-doped and undoped CuO targets, respectively, were measured in order to examine the mechanisms of carrier generation and transport in doped films. The temperature dependence of the carrier density of the films revealed that regardless of the Ni content, the activation energies of the acceptor level of the films are 0.22-0.25 eV. The temperature dependence of the mobility of the films changed from −0.58 to ∼0 by doping with Ni. These results evidenced that hole carriers in Ni-doped Cu₂O as well as in undoped Cu₂O were generated by Cu vacancies and were primarily scattered by neutral impurity scattering centers. X-ray diffraction (XRD) measurements of the films showed that the mass fraction of Cu₂O in the films decreased with increasing Ni content, while that of CuO increased. It was also found that the reduction process of CuO to Cu₂O was suppressed by the Ni doping.     

Green synthesis of bi-component copper oxide composites and enhanced photocatalytic performance

A facile and green route was proposed for the synthesis of bi-component copper oxide composite without any templates and additives. The effects of D-(+)-glucose amount, reaction temperature, and reaction time on the morphology and constitution of the products were investigated by SEM, X-ray diffraction, and UV-vis DRS in detail. The results indicate that a series of Cu₂O–CuO bi-component copper oxide composites with various morphologies can be easily obtained. Structure characterisation and photocatalytic tests show that the bi-component Cu₂O–CuO composites exhibited better photodecolouration of methylene blue than those of the Cu₂O, CuO, and Cu–CuO compounds owing to the existence of the synergistic effect between the CuO and Cu₂O.     

Ultrasound assisted template-free synthesis of Cu(OH)2 and hierarchical CuO nanowires from Cu7Cl4(OH)10·H2O

Cu(OH)₂ nanowires have been synthesized by an ultrasound assisted solution route in absence of a template, using Cu₇Cl₄(OH)₁₀·H₂O as a precursor. Hierarchical CuO nanowires were obtained by a simple solid-state thermal transformation of these Cu(OH)₂ nanowires. The products were characterized by XRD, SEM, TEM and HRTEM. The ranges of diameters and lengths of the polycrystalline CuO nanowires are ca. 20-30 nm and several micrometers, respectively. Ultrasonic time is found an important factor to morphology of the CuO products. This could be a potential efficient way for large scale fabrication of CuO nanowires with hierarchical structures. Surface photovoltage spectra of the CuO nanowires in air, NH₃ and CH₂Cl₂ atmospheres were investigated, which demonstrates it a good photoelectric gas sensing material.