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TiO2 photocatalyst was supported with tetrabutyl titanate sol as precursor and fine silicon powder obtained from ferroalloys factory as carder to discuss the influence of pH value of gel precursor on microstructure and activity of photocatalyst in the process of synthesizing nano-TiO2 by using sol-gel method, the purpose of which is to provide fundamental data for the recycle of photocatalytic material. Under the irradiation of ultraviolet light, the photocatalytic degradation rate of methyl orange solution was used to characterize the photocatalytic activity of the sample. The specific surface area of the sample was tested by N2 desorption method, crystal form of TiO2 was analyzed by X-ray powder diffraction, and the microtopography of the sample was observed by scanning electron microscopy. The experimental results showed that the acidity of gel precursor could greatly affect the specific surface area and photocatalytic activity of the photocatalyst, and the optimum pH value of the precursor was determined as 2.0, and at this time the specific surface area of photocatalyst could reach 34.0 m^2/g. In the sample, the proporticn of anatase to rutile is 7:3, which makes l0 mg·L^-1 methyl orange solution fade after irradiation by 15W ultraviolet light for 24 h, and the degradation rate might be up to 98.1%. 相似文献
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铁合金厂回收的硅微粉在不同温度下晶相结构的研究 总被引:13,自引:0,他引:13
铁合金厂冶炼过程产生的大量硅微粉烟尘, 可以作为耐火材料和窑具材料的结合剂, 活性剂和矿化剂, 可促进耐火材料固相反应和烧结, 有利于晶型的转变, 提高耐火材料的高温性能。硅微粉在高于或等于1100 ℃不析晶。1200和1300 ℃析晶规律是:首先α-石英转变为α-方石英, 然后转变为α-鳞石英。在1400~1450 ℃首先析出卡片号为290085的石英变体, 然后转变为α-方石英。 而常规转化过程是α-方石英很难形成α-鳞石英, 而且不形成290085的变体, 因此其转化规律与常规不同。在液相存在情况下, 少量α-方石英转变为α-鳞石英, 不同温度下析晶结构探讨为实际生产提供适宜的升温曲线。 相似文献
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By adding small amount of TiO2, aluminum slag could be used to synthesize cor-dierite, α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X‘pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly. 相似文献
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采用动力学方法研究了MnO2颗粒物对TiO2光催化降解苯胺活性的影响,对比考察了光催化降解过程中苯胺溶液的UV吸收光谱的变化,并用HPLC方法鉴别了中间产物.结果表明,少量MnO2颗粒物就能使TiO2光催化降解苯胺的活性受到明显的抑制,不同结构的二氧化锰致毒效应由大到小的顺序为:δ-MnO2α-MnO2β-MnO2;降解不同时间后溶液的UV吸收光谱的变化也反映了MnO2颗粒物具有同样的致毒效应;MnO2颗粒物不改变TiO2光催化降解苯胺的途径,但对生成中间产物的基元步骤的抑制程度不同。 相似文献
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利用X-射线衍射分析和电子显微镜分析的结果,确定堇青石窑具的多晶结构和各晶相的含量;结合窑具性能的研究,确定堇青石窑具具有优良性能的适宜配方。 相似文献
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WU Ren-Ping GUO Jin-Yu Chen Zhu-Ling YU Yan② 《结构化学》2008,27(10):1245-1249
Recoverable TiO2 photocatalysis material supported by silicon powder was prepared with sol-gel method, afterwards the silica gol and sodium silicate were used as molding binder respectively to investigate their effects (including binder type and binder addition quantity) on the crystal structure and catalysis properties of photocatalyst. In this work, the catalysis activity was defined as the degradation rate of methyl orange solution upon ultraviolet lamp irradiation, and the specific areas were determined with nitrogen desorption method. TiO2 crystal form was measured with X-ray powder diffraction and their micro-morphology was observed with SEM. Experimental results indicate that these two binders do not affect the crystal form transformation of TiO2, but silica gol can increase the specific surface area of TiO2 photocatalyst obviously and the addition of sodium silicate can decrease it. In all, silica gol is a better candidate than sodium silicate for higher catalysis property. In conclusion, 6% silica gol is the optimal addition concentration. Under this condition, the ratio of anatase to rutile TiO2 is 64:36, the specific area is 29.67 m^2/g, and as expected, the degradation rate of methyl orange could be as high as 90% after irradiation for 5 days. 相似文献
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RUAN Yu-Zhong ② YU Yan WU Ren-Ping 《结构化学》2006,25(8):965-970
1 INTRODUCTION The mullite has excellent properties of high tem- perature thermodynamics and mechanics, such as corrosion resistance, creep resistance, thermal shock resistance and high hot strength at high temperature. So it can be used as the inner lining of industrial furnace, thermal insulator material, crucible, protec- ting tube and electronic packaging material, which are widely used in such industries as metallurgy, ceramics, cement, and fireproof materials[1]. So far there has no … 相似文献
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在微波辐射作用下三环己基氢氧化锡和喹啉甲酸按物质的量比1∶1反应,合成了标题化合物晶体。经X-射线衍射方法测定了其晶体结构,属三斜晶系,空间群为P1。晶体中每一个结构基元包含了2个锡原子为六配位的畸变八面体构型单锡核配合物分子、1个锡原子为五配位的畸变三角双锥构型双锡核配合物分子和2个水分子。对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及部分前沿分子轨道的组成特征。研究了配合物的热稳定性、电化学性能和荧光性质。 相似文献
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Crystal Structure of Cesium Phenylacetylide,CsC2C6H5, Solved and Refined from Synchrotron Powder Diffraction Data 下载免费PDF全文
The crystal structure of cesium phenylacetylide, CsC2C6H5, was solved and refined from synchrotron powder diffraction data (Pbca, Z = 8). Each Cs+ cation is coordinated by five ligands: four acetylide groups coordinate side‐on and one end‐on. A similar arrangement is found in the crystal structure of NaC2H (P4/nmm, Z = 2). There is a group‐subgroup relationship between both structures. Most importantly, the crystal structure of CsC2C6H5 could only be solved with the help of synchrotron data, as the very good peak:noise ratio allowed the assignment of several very weak reflections, which finally led to the correct space group, in which a structural solution was possible using direct space methods. 相似文献
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Magnesium dicyanamide tetrahydrate Mg[N(CN)2]2 · 4 H2O was synthesized by aqueous ion exchange starting from Na[N(CN)2] and Mg(NO3)2 · 6 H2O. The crystal structure was solved and refined on the basis of powder X‐ray diffraction data (P21/c, Z = 2, a = 737.50(2), b = 732.17(1), c = 971.67(2) pm, β = 98.074(1)°, wRp = 0.059, Rp = 0.046, RF = 0.075). In the crystal there are neutral complexes [Mg[N(CN)2]2(H2O)4] which are only connected via hydrogen bonds. Above 40 °C the tetrahydrate decomposes into anhydrous Mg[N(CN)2]2. 相似文献
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采用不同比例的乙酰丙酮铝[Al(AcAc)3]与聚硅碳硅烷(PSCS)反应制备含铝碳化硅陶瓷的先驱体聚铝碳硅烷(PACS). 采用气相凝胶色谱(GPC)、化学分析和红外等手段对不同铝含量的PACS组成和结构进行了表征, 研究了铝含量对PACS结构和性能的影响. 结果表明, 随着铝含量的增加, PACS的氧含量增加, 分子量分布变宽, 主要活性基团Si—H键的含量降低, PACS的可纺性降低. 当Al(AcAc)3/PSCS(质量比)大于20%以后, PACS不可纺. 热重-差热分析(TG-DTA)的研究表明: 当制备PACS的Al(AcAc)3/PSCS(质量比)大于4%, PACS在N2中400~560 ℃之间的失重明显降低. 铝含量在0.4~0.7 wt%的PACS, 制备的Si-Al-C-O纤维抗张强度最高. Al(AcAc)3/PSCS=6 wt%时制备的PACS, 烧结的SiC(Al)纤维最致密. 相似文献
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二维含镧链异核金属化合物的合成、结构和磁性研究 总被引:1,自引:0,他引:1
水热法合成了3个层状异核金属化合物[Ln(idaH)M(ida)2]n·0.5nH2O,(H2ida=亚氨基二乙酸,Ln=Nd,M=Co (1);Ln=La,M=Co (2);Ln=La,M=Ni (3))。进行了晶体结构测定,红外光谱分析、能谱分析与磁性能分析。3个化合物除金属原子不同外具有相同的结构,其晶体都属于单斜晶系,C2/c空间群。单晶结构表明该结构含有由十配位的Ln通过羧基氧连接而成的链,六配位的3d金属(Co、Ni)交替地处在链的两边,形成了带状结构,带状链通过配体连成二维结构,通过氢键形成三维骨架。 相似文献