SnO_2 nano-sheet as an efficient catalyst for CO oxidation

Polycrystalline SnO2 fine powder consisting of nano-particles （SnO2-NP）, SnO2 nano-sheets （SnO2-NS）, and SnO2 containing both nano-rods and nano-particles （SnO2-NR＋NP） were prepared and used for CO oxidation. SnO2-NS possesses a mesoporous structure and has a higher surface area, larger pore volume, and more active species than SnO2-NP, and shows improved activity. In contrast, although SnO2-NR＋NP has only a slightly higher surface area and pore volume, and slightly more active surface oxygen species than SnO2-NP, it has more exposed active （110） facets, which is the reason for its improved oxidation activity. Water vapor has only a reversible and weak influence on SnO2-NS, therefore it is a potential catalyst for emission control processes.

SnO_2-based solid solutions for CH_4 deep oxidation: Quantifying the lattice capacity of SnO_2 using an X-ray diffraction extrapolation method

A series of SnO2‐based catalysts modified by Mn, Zr, Ti and Pb oxides with a Sn/M （M=Mn, Zr, Ti and Pb） molar ratio of 9/1 were prepared by a co‐precipitation method and used for CH4 and CO oxidation. The Mn3＋, Zr4＋, Ti4＋and Pb4＋cations are incorporated into the lattice of tetragonal rutile SnO2 to form a solid solution structure. As a consequence, the surface area and thermal stability of the catalysts are improved. Moreover, the oxygen species of the modified catalysts become easier to be reduced. Therefore, the oxidation activity over the catalysts was improved, except for the one modified by Pb oxide. Manganese oxide demonstrates the best promotional effects for SnO2. Using an X‐ray diffraction extrapolation method, the lattice capacity of SnO2 for Mn2O3 was 0.135 g Mn2O3/g SnO2, which indicates that to form stable solid solution, only 21%Sn4＋cations in the lattice can be maximally replaced by Mn3＋. If the amount of Mn3＋cations is over the capacity, Mn2O3 will be formed, which is not favorable for the activity of the catalysts. The Sn rich samples with only Sn‐Mn solid solution phase show higher activity than the ones with excess Mn2O3 species.

Investigation on preparation of CuO-SnO_2-CeO_2/γ-Al_2O_3 catalysts for catalytic wet air oxidation process and their catalytic activity for degradation of phenol

Catalytic Wet Air Oxidation process is an efficient measure for treatment of wastewater with great strength which is not biodegradable. Heterocatalysts now become the key investigation subject of catalytic wet air oxidation process due to their good stability and easy separation. In the paper, CuO-SnO2-CeOγ-Al2O3 catalysts are prepared by impregnation method, with SnO2 as a doping component, CuO as an active component, CeO2 as a structure stabilizer, γ-Al2O3 as a substrate. XPS test is carried out to investigate the effect of Sn on the chemical surrounding of Cu and O element on the catalyst surface and their catalytic activity. It is shown that the right doping of Sn can increase Cu^＋ content on the catalyst surface, as a result the quantity of adsorption oxygen is also increased. It is found that Cu^＋ content on the catalyst surface is one of the primary factors that determin catalytic activity of catalyst through analyzing the catalytic wet air oxidation process of phenol.

The Characteristic of Electrochemical Oxidation of Aniline on SnO_2/Ti Electrode

The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.

Electrochemical Oxidation of Chlorimuron-ethyl on Ti/SnO_2-Sb_2O_5/PbO_2 Anode for Waste Water Treatment

The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography（HPLC）, and the chemical oxygen demand（COD） was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.

PbO_2和SnO_2电极电氧化纸业废水中木质素褪色和降解效果的研究

纯的和掺杂金属离子的PbO2 和SnO2 电极对电氧化纸业废水中木质素褪色和降解表现出一定的活性.当SnO2 电极掺杂Ni(II)后 。

CO在超细SnO_2和Pd/SnO_2上的催化氧化

采用溶胶凝胶——超临界流体干燥法制备ＳｎＯ２粉体和负载Ｐｄ催化剂。考察了ＣＯ催化氧化活性、稳定性及焙烧还原条件的影响。结果表明：超细ＳｎＯ２及负载Ｐｄ催化剂的催化氧化活性明显优于一般ＳｎＯ２，它们的最佳焙烧温度和适宜的还原温度分别为６００℃和５０℃。

新型多孔Ti/Sb2O4-SnO2电极的制备及性能

以采用脱合金方法制备的具有纳米多孔结构的钛板为基体,通过电沉积方法和热分解法成功制备了锡锑氧化物电极(Ti/Sb2O4-SnO2)。利用X射线衍射、扫描电子显微镜、透射电子显微镜对电极的相组成、微观形貌进行表征。应用电化学工作站测试电极的电化学性能,并研究了电极对苯酚的电催化氧化降解能力。通过调节钛基体热处理温度来优化电极性能,结果表明:多孔钛基体热处理温度为300℃时,制备的Ti/Sb2O4-SnO2电极多孔网状结构明显清晰,电流密度最大,导电性最好,电极实际寿命达到251.6 h,电极电阻最小,约为14.5Ω,90 min对苯酚的降解效率最高,约为97%。

Preparation and electrocatalytic property of Au-Pt/SnO_2/GC composite electrode

Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon （GC）. Atomic force microscopy （AFM） and scanning electron microscopy （SEM） images revealed that dense and uniform Au-Pt particles with 25-nm diameter were dispersed on SnO2 film. X-ray photoelectron spectroscopy （XPS） results proved that there was an interaction between Au-Pt nanoparticles and SnO2 support. Electrochemical experiments showed that Au-Pt/SnOz/GC composite electrode had a good electrocatalytic activity to the oxidation of methanol

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+.

Chemical Investigation of the NO_x Detection Mechanisms by Semiconductor Metal Oxide Nanoparticles

This work reports an FTIR study of the NO_x adsorption/desorption cycles on tin oxide nanosized particles under the operating conditions of real sensors (150℃,in presence of O_2).The chemical reactions are monitored in situ and correlated with the variations of the SnO_2 electrical conductivity.On the basis of the FTIR spectra,two contributing mechanisms for the NO_x detection are suggested.The first one presents the formation of bridged nitrate groups bound to the SnO_2 surface via oxygen vacancies acting as electron donor sites.The second mechanism also involves surface oxygen vacancies in the coordination of NO_x,but this time the formation of NO_x anionic species is considered.Both mechanisms lead to the decrease of the electrical conductivity under NO_x adsorption.However,the bridged nitrate groups are not reversible under gas desorption and thus irreversibly contaminate the surface after the first NO_x adsorption.On the contrary,the nitrosyl anionic species are reversible and,from the second NO_x adsorption/desorption cycle,ensure the reproducibility of the sensor response.

TRANSPARENT AND CONDUCTIVE OXIDE FILM GROWTH AND APPLICATION

Thin layer polycrystal oxides (amorphous and micro-crystalline) TiO2(Fe2O3, SnO2 and ln2O3 · Sn) are prepared by the organometallic chemical vapor deposition (MO-CVD) technique at 300-410℃ . Their structures, surface states and photoelectrochemical properties are described by X-ray diffraction (XRD), electron microscopy and three electrode methods. The experiments indicate that these thin layer oxides are suitable for formly transparent conductive coating to serve as photoelectrodes and photocatalysts for splitting of water.

Inducing the SnO2-based electron transport layer into NiFe LDH/NF as efficient catalyst for OER and methanol oxidation reaction

In an electrocatalyst with a heterointerface structure,the different interfaces can efficiently adjust the catalyst’s conductivity and electron arrangement,thereby enhancing the activity of the electrocatalyst.Ultrathin and smaller Ni Fe LDH was successfully constructed on the surface of SnOnanosheet supported NF by layer by layer assembly,and exhibits lower overpotential of 234 mV at a current density of 10 m A cm,which only increases by 6.4%even at a high current density of 100 mA cm.The excellent OER activity of catalyst is attributed to the contribution of the semiconductor SnOelectron transport layer.Through experiments and characterization,3d structure SnOnanosheets control the growth of ultra-thin nickel-iron,the hierarchical interface between SnOand Ni Fe LDH can change the electron arrangement around the iron and nickel active centers at the interface,resulting the valence states of iron slightly increased and Nicontent increased.The result will promote the oxidation of water.Meanwhile,the SnOsemiconductor as electron transport layer is conducive to trapping electrons generated in oxidation reaction,promoting electrons transferring from the Ni Fe LDH active center to the Ni substrate more quickly,and enhance the activity of Ni Fe LDH.It also shows excellent activity in an electrolyte solution containing 0.5 M methanol and 1 M KOH,and only 1.396 V(vs.RHE)is required to drive a current density of 10 mA cm.

Anodic oxidation of azo dye C.I. Acid Red 73 by the yttrium-doped Ti/SnO2-Sb electrodes

This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 （ART3） using the yttrium-doped Ti/SnO2-Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomposition temperature and cycle times of dip-coating thermal decomposition on the properties of the electrodes were investigated. The results showed that the excellent electrochemical activity of Ti/SnO2-Sb-Y electrode can be achieved at a 7：1 molar ratio of Sn：Sb and thermal decomposition temperature of 550~C. Moreover when the cycle times of dip-coating and thermal decomposition were up to 10 times, the performance of the electrode tends to be stable. The Ti/SnO2-Sb electrodes doped with yttrium （0.5 tool-%） showed the most excellent electrochemical activity. In addition, the influences of operating variables, including current density, initial pH, dye concentration and support electrolyte, on the colour removal, chemical oxygen demand （COD） removal and current efficiency were also investigated. Our results confirmed that the current efficiency increased with the concentrations of dye and sodium chloride. Moreover, increasing the current density and the initial pH would reduce the current efficiency.

Active Stainless Steel/SnO_2-CeO_2 Anodes for Pollutants Oxidation Prepared by Thermal Decomposition

Stainless steel plates were successfully coated with SnO2-CeO2 films （SS/SnO2-CeO2） by brush coating with a solution of stannous chloride and cerium trichloride followed by thermal decomposition. It is proven that the properties of SnO2 films can be evidently improved by Ce doping, and 600℃ is the optimum temperature to prepare SS/SnO2-CeO2 anodes. The physicochemical and electrochemical properties as well as the elec- trocatalytic activity of the electrodes were investigated. It is found that the novel electrodes have compact microstructure, high overpotential for oxygen evolution （1.60 V vs SCE）, excellent electrochemical stability, relatively low cost and excellent catalytic activity for oxidizing pollutants. An industrial dye wastewater, which is hard to be purified by using conventional chemical flocculation methods, was oxidated by employing the SS/SnO2-CeO2 anodes, and 83.00% of color and 48.62% of chemical oxygen demand （COD） removal was achieved under the cell voltage of 5 V within only 2 min, and the electricity consumption is only 1.83 kWh for oxidizing I m3 of dye wastewater.

锂离子电池锡负极材料研究进展

简要介绍了研究较多的碳负极材料 ,重点评述锡负极材料与锂的反应机理、制备方法、结构与电化学性能之间的关系及近期的研究现状。随着新的制备方法和新的分子结构设计的出现 ,若能克服目前所存在的问题 。

电化学方法用于酸性红B模拟废水脱色试验研究

本文研究了两种电极材料 (SnO2 Ti和RuO2 Ti)对酸性红B模拟废水的脱色效果 ,考察了不同 pH、电流密度(j)及外加电解质 (Na2 SO4/NaCl)对处理过程的影响。结果表明 ,两种电极材料都能对酸性红B染料废水进行有效脱色 ,主要是Cl-在电解过程中的间接氧化作用 ,同时也包括电极表面的直接氧化作用。

二氧化锡非晶超微粒薄膜制备与薄膜性能的研究

我们用ＰＥＣＶＤ（等离子激活化学气相沉积）方法制备ＳｎＯ２薄膜。透射电镜表明４００℃以下是非晶状态，扫描电镜测试表明颗粒度为３０ｎｍ，ＳｎＯ２薄膜的紫外可见反射吸收光谱中，沉积在石英上的ＳｎＯ２薄膜出现价带到导带本征吸收带，可计算出非晶ＳｎＯ２薄膜禁带宽为３．５４ｅＶ，ＳｎＯ２薄膜红外光谱研究表明：ＳｎＯ２非晶薄膜随着加热温度升高，有序化程度升高，在３００℃明显出现５７２ｃｍ－１的ＳｎＯ２骨架振动带。经３００℃老化样品只对醇敏感。为制备好的气敏材料提供理论基础。

La-Ba-Sn(Sm,Ce)体系催化剂上的甲烷氧化偶联

报道了Ｌａ－Ｂａ－Ｓｎ（Ｓｍ，Ｃｅ）体系催化剂上甲烷氧化偶联反应（ＯＣＭ）的催化性能．实验结果表明：第三组分Ｓｎ、Ｓｍ、Ｃｅ的添加显著提高了ＯＣＭ催化活性和Ｃ２烃选择性．不同催化剂制备方法对催化活性的影响不同，混浆法低温焙烧有利于低温ＯＣＭ反应；干混法高温焙烧能在最佳ＯＣＭ反应条件下获得较高的Ｃ２烃收率和选择性．

玻璃熔液测温用热电偶保护管的研制

研究了氧化物添加剂对氧化锡陶瓷性能的影响。选出一种适于高温玻璃熔池测温用的热电偶保护套管材料 ,并用冷等静压法制造出该种热电偶保护套管。