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1.
纳米复合Sb2O3/TiO2的光催化性能研究   总被引:36,自引:0,他引:36       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.
纳米复合Sb_2O_3/TiO_2的光催化性能研究   总被引:7,自引:0,他引:7  
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
3.
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射线粉末衍射进行了表征,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)nm,b=1.19121(8)nm,c=1.23588(8)nm,β=126.822(1)°,V=1.6499(2)nm^3,Dc=2.439g·cm^-3,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
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.
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
7.
Subsolidus phase relation studies in the NaSb3O7-Na3SbO4-CuO-CuSb2O6 quadrangle of Na2O-CuO-Sb2On system at 1123-1173 K revealed the formation of one new compound Na3Cu2SbO6. It is a superstructure derived from α-NaFeO2 type, space group C2/m, lattice constants: a=5.6759(1) Å, b=8.8659(1) Å, c=5.8379(1) Å, β=113.289(1)°. All ions are in octahedral environment, but CuO6 polyhedron exhibits strong elongation due to Jahn-Teller effect (Cu-O: 2.000(2) Å×2, 2.021(2) Å×2, 2.494(3) Å×2), whereas SbO6 octahedron is almost regular. The relationship to other similar superlattices is discussed.  相似文献
8.
Sb/ZSM-5 was obtained by solid-state reaction with the mixture of Sb2O3 and zeolite HZSM-5 under a dry nitrogen flow at 773 K. Characterization of the treated zeolite was undertaken with XRD, 27Al MAS NMR, BET, TGA and FT-IR. The results revealed that part of the antimony oxides migrated into the channels of zeolite, and decreased the Brönsted acid sites in Sb/ZSM-5 remarkably. The other part of antimony oxides together with the amorphous alumino-silicate in the products distributed on the external surface of zeolite ZSM-5 and modified it, while the framework of ZSM-5 in crystal phase was retained. The structure of occluded antimony oxide inside the channels of ZSM-5 was studied by XRD Rietveld method. The result showed that their structure can be described as a chain of non-perfect [Sb5O5(H2O)2]n5n+, which is parallel to the straight channel of ZSM-5. There is about 0.6 [Sb5O5(H2O)2]5+ unit in every cell of the ZSM-5 on an average.  相似文献
9.
Investigations on Sb2O4 at high pressure and temperature have been performed up to 600 °C and up to 27.3 GPa. The so-called “high temperature” phase (β-Sb2O4) was obtained following pressure increase at ambient temperature and at relatively low temperatures. Thus, in contrast to previous perceptions, β-Sb2O4 is the modification more stable at high pressures, i.e., at low temperatures. The fact that the metastable α-form is typically obtained through the conventional way of preparation has to be attributed to kinetic effects. The pressure-induced phase transitions have been monitored by in-situ X-ray diffraction in a diamond anvil cell, and confirmed ex-situ, by X-ray diffraction at ambient conditions, following temperature decrease and decompression in large volume devices. Bulk modulus values have been derived from the pressure-induced volume changes at room temperature, and are 143 GPa for α-Sb2O4 and 105 GPa for the β-Sb2O4.  相似文献
10.
Single crystals of a new compound of formula MnVSbO6 were grown by slow cooling from a V2O5-B2O33 flux at 900°C. The compound crystallizes in the orthorhombic space group Pbcn (No. 60), with cell parameters (in the Pcnb setting) a=4.6604(3) Å, b=4.9603(3) Å, c=17.1433(9)Å, Z=4. The crystal structure was solved from 1188 independent reflections to Rw=3.20% and goodness-of-fit 1.5 for 44 refined parameters. The structure can be described as a superstructure of the α-PbO2 type with a cation ordering similar to that found in Fe2WO6. Cations occupy octahedral sites in the PbO2-like layers. Zigzag chains of edge-sharing MnO6 octahedra alternate with mixed Sb/V chains following a -Mn-Sb/V-Sb/V- sequence. The magnetic susceptibility of MnVSbO6 follows the Curie-Weiss law down to ca. 15 K, where it orders antiferromagnetically. The bond lengths and Curie constant are consistent with the expected charge distribution Mn2+V5+Sb5+O6.  相似文献
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