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1.
纳米复合Sb2O3/TiO2的光催化性能研究   总被引:35,自引:0,他引:35       下载免费PDF全文
采用溶胶-凝胶法制备复合纳米Sb2O3/TiO2Sb2O3掺入浓度越大,催化剂中锐钛矿相含量越高,晶粒直径与颗粒直径越小,比表面积越大,在380-460nm,范围内,Sb2O3/TiO2的反射率则减弱,表明光吸收增强,Sb^5+,占48.42%、Sb^ 占17.58%,以亚甲基蓝溶液光催化降解为模型反应,掺入2%,5%Sb2O3,亚在蓝溶液的光催化脱色降解一致动力学常数与总有机炭(TOC)去除率增大,发射光谱证明,Sb2O3的最佳比例为2%,当其比例大于2%时,其电子空穴对的复合率升高,光催化活性下降。  相似文献
2.
巯基乙酸锑(Ⅲ)配合物合成与晶体结构   总被引:7,自引:1,他引:6       下载免费PDF全文
以三氧化二锑和巯基乙酸在水溶液中反应合成了配合物HSb(SCH2COO)2,并通过元素分析、红外光谱、X射线物末衍射进行了表征,利用单晶X射线四圆衍射法测定了晶体结构.结果表明该配合物晶体属于单斜晶系,C2/c空间群.晶胞参数为a=1.40005(8)m.b=1 19121(8)nm,c=1.23588(8)nm,β=126.822(1).,V=1.6499(2)nm3,D=2.439 g@cm3,Z=8,R1=0.0250.并对X射线粉末衍射数据进行了指标化,其结果与单晶数据吻合  相似文献
3.
纳米复合Sb_2O_3/TiO_2的光催化性能研究   总被引:6,自引:0,他引:6  
采用溶胶-凝胶法制备复合纳米 Sb2O3/TiO2。 Sb2O3掺入浓度越大,催化剂中锐钛矿相含量越高,晶粒直径与颗粒直径越小,比表面积越大。在 380~ 460nm范围内, Sb2O3/TiO2的反射率则减弱,表明光吸收增强。 XPS分析表明:掺入 2% Sb2O3,出现新的 Ti2p3/2峰,对应于 Ti3+,占 9.13%;锑以 Sb3+、 Sb5+两种形式存在, Sb5+占 84.42%、 Sb3+占 17.58%。以亚甲基蓝溶液光催化降解为模型反应,掺入 2%、 5% Sb2O3,亚甲基蓝溶液的光催化脱色降解一级动力学常数与总有机炭( TOC)去除率增大。发射光谱证明: Sb2O3的最佳比例为 2%,当其比例大于 2%时,其电子空穴对的复合率升高,光催化活性下降。  相似文献
4.
Selective catalysts for the production of nitrogen-containing compounds   总被引:2,自引:0,他引:2  
Herewith are the two processes developed by Nitto, which produce N-containing compounds such as hydrogen cyanide and methylamines. These processes are characterized by unique selective catalysts: an Fe–Sb–O based fluid-bed catalyst for ammoxidation of methanol and a shape-selective zeolite catalyst for ammonolysis of methanol.  相似文献
5.
丙烷氨氧化V/Sb系复合氧化物催化剂的研究   总被引:1,自引:0,他引:1  
考察了不同组成的V-Sb-O系复合氧化物对丙烷氨氧化的催化活性。用XRD研究了催化剂的结构,利用程序升温方法研究了催化剂中氧的活动性和表面酸碱性,讨论了催化剂体相和表面结构与催化性能间的关系。结果表明,VSbO4和Sb2O4间的协同作用是影响催化活性的重要因素。  相似文献
6.
 Antimony nanocrystals were formed in thin SiO2 films using low-energy ion implantation of Sb followed by annealing. Using Fourier transform laser microprobe mass spectrometry (FT LMMS), we observed for the first time the presence of antimony oxide in the intermediate phase (as-implanted layer of Sb) by means of signals referring to the intact Sb2O3 molecules. Only SbO+ fragments, but no adduct ions of Sb2O3 could be detected in annealed samples. The size and the distribution of the nanocrystals formed around the initial depth of implantation were studied in the as-implanted samples by high-resolution electron microscopy (HREM). The crystalline structure of these nanocrystals was also studied and the presence of antimony trioxide Sb2O3 in the form of valentinite was proven. After the annealing step, the implanted material had spread into a wider band. The method introduced here, based on combining TEM (transmission electron microscopy) and FT LMMS results, offers the possibility of studying the evolution of the phases in Sb nanocrystal formation.  相似文献
7.
 The hydrolysis of SbCl3 in hydrochloric acid solution (2.0 mol dm-3 HCl) at 0 °C yields an amor-phous product consisting of uniform spherical particles (d∼0.5 μm), which on continuous aging at the same temperature transform to larger crystals, indicated by XRD to be Sb4O5Cl2. In contrast, in the same solution kept at 25 °C crystalline particles of the same composition form directly after an induction period and then grow with time. The final products, obtained at 0 °C and 25 °C consist of aggregated subunits. These powders on calcination in nitrogen are converted to Sb2O3 and in air to Sb2O4. Received: 23 June 1997 Accepted: 1 July 1997  相似文献
8.
The thermal decomposition of the only known antimony nitrate antimony(III) oxide hydroxide nitrate Sb4O4(OH)2(NO3)2, whose synthesis routes were reviewed and optimized was followed by TG-DTA under an argon flow, from room temperature up to 750°C. Chemical analysis (for hydrogen and nitrogen) performed on samples treated at different temperatures showed that an amorphous oxide hydroxide nitrate appeared first at 175°C, and decomposed into an amorphous oxide nitrate above 500°C. Above 700°C, Sb6O13 and traces of -Sb2O4 crystallized.Author to whom all correspondence should be addressed  相似文献
9.
SiO2/SnO2=80/20 gel samples are prepared from Si(OEt)4 and SnCl4 or Sn(OEt)4. Samples doped with Sb oxide contents up to 4% are also studied. The evolution of these samples after treatment from room temperature to 1050°C is studied by 119Sn M?ssbauer spectroscopy and X-ray analysis. Results indicate that SnO2 separation depends on preparation method and Sn- or Sb-oxide precursors. In the case of Sn(OEt)4, hydrolysis is less complete than for SnCl4 and thermal curing affords charcoal separation which leads to extensive reduction of Sn(IV) to Sn(II). Products obtained above 800°C are constituted by a well-defined SnO2 phase in the SiO2 matrix. Segregation of Sn(II) and subsequent oxidation to Sn(IV) are invoked to account for this final morphology. The presence of Sb oxide lowers Sn(IV) reduction and favours both SnO2 and SiO2 crystallization, via the occurrence of a Sn/Sb-oxide metastable phase observed in the 700–800°C interval.  相似文献
10.
Previous reports of the thermal behaviour of antimony trioxide show significant disagreement on the values for the temperatures associated with specific thermal events. In this reappraisal, samples of both polymorphs of Sb2O3 (senarmontite and valentinite) have been analysed using X-ray diffraction and simultaneous differential thermal/thermogravimetric analysis techniques. The senarmontite-valentinite phase transition has been observed to occur as a multi-stage event commencing at temperatures as low as 615±3 °C—evidence of oxidation to Sb2O4 under inert atmosphere may indicate that the depression is related to surface- or bulk-bound water. Valentinite produced by mechanical milling of senarmontite exhibits the reverse phase transition to senarmontite at a lower than normal temperature (445±3 °C). Oxidation temperatures of 531±4 °C for senarmontite and 410±3 °C for mechanically derived valentinite were also recorded.  相似文献
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