电合成纳米NiAl_2O_4、LiTi_2O_4前驱体及溶胶—凝胶法制备纳NiAl_2O_4、LiTi_2O_4粉体
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摘要
电化学方法制备金属醇盐，是以惰性电极为阴极，以欲制备其醇盐的金属为“牺牲”阳极，在醇溶液中加入少量导电盐，通电流使阳极溶解，阴极发生还原反应制备金属醇盐。溶胶—凝胶法，是通过金属醇盐的水解、浓缩，低温合成具有特殊结构、高纯度、及粒度均匀的纳米级粉体的有效方法。
本文采用恒电流电解技术，在醇中加入少量有机铵导电盐作为电解液，加入0.35g锂片，制成锂醇盐；再以纯钛金属作为阳极，控制电流为0.2A，电解4.5h，得到锂、钛的醇盐溶液，作为制备纳米LiTi2O4的前驱体；然后直接水解，经溶胶-凝胶(Sol-gel)过程，形成纳米LiTi2O4凝胶；在450℃锻烧2h，得到纳米粉体LiTi2O4。通过IR、TG-DTA、XRD、TEM等检测手段，对锂、钛醇盐和纳米LiTi2O4进行了表征。结果表明，电化学溶解金属阳极--直接水解法制得的纳米LiTi2O4粉体平均粒径在10-15mm左右。
“牺牲”阳极法制备纳米NiAl2O4的方法与制备LiTi2O4相似，经溶胶-凝胶(Sol-gel)过程制得纳米NiAl2O4。水解粉体在350oC煅烧2h,采用红外（IR）、差热-热重分析（TG-DTA）、X-射线衍射（XRD）、电子透射技术（TEM）等手段对前驱体和纳米NiAl2O4进行了表征。结果表明，电解法可以在低温下制备得到纳米NiAl2O4粉体，粉体具有一定的热稳定性，呈单分散结构，平均粒径在10-20nm之间。为超纯纳米材料的制备提供了一条新途径。
The electro-synthesis of metal alkoxide used pure metal as sacrificial anode and inertia electrode as cathode. Current passed through the absolute alcohol solution with the electro-conductive additive, and metal anode was dissolved and reducing reaction occurred on cathode. The Sol-gel process, which was based on the hydrolysis and condensation of metal alkoxide, could synthesize nanometer material with a special structure , high purity and well-proportioned granularity at a low temperature.
In this paper, the organic ammonium was used as electro-conductive additive. 3.5g lithium slice was added in the ethanol and acetyl-acetone solution, and then the precursor of the nano-LiTi2O4 powder was synthesized by anodic dissolution of titanium at the current of 0.2A for 4h. Nano-LiTi2O4 powder was prepared for by a direct sol-gel process of the electrolyte solution and calcining at the temperature of 4500C for 2h. IR. spectrum, TG-DTA, XRD, and TEM were used to investigate the structure of the precursor and the nano- LiTi2O4 powder. The result showed that the nano-sized LiTi2O4 with a narrow distribution of 10-15 nm was obtained by the electrochemical dissolution following hydrolysis.
The measure, by which nano-NiAl2O4 was synthesized, is similar with that of LiTi2O4 . Nano-sized NiAl2O4 was prepared for by a direct sol-gel process of the electrolyte solution. The structures of the precursor and its nano-sized powder were investigated by IR. spectrum ,TG-DTA, XRD, and TEM. The experiment showed that nano-sized NiAl2O4 with a narrow distribution of 10-20 nm was obtained at a low temperature of 3500C, and it possessed a certain heat stability and a disperse structure. This process may be recommended as a promising method to synthesize other composite nano-powders.
本文采用恒电流电解技术，在醇中加入少量有机铵导电盐作为电解液，加入0.35g锂片，制成锂醇盐；再以纯钛金属作为阳极，控制电流为0.2A，电解4.5h，得到锂、钛的醇盐溶液，作为制备纳米LiTi2O4的前驱体；然后直接水解，经溶胶-凝胶(Sol-gel)过程，形成纳米LiTi2O4凝胶；在450℃锻烧2h，得到纳米粉体LiTi2O4。通过IR、TG-DTA、XRD、TEM等检测手段，对锂、钛醇盐和纳米LiTi2O4进行了表征。结果表明，电化学溶解金属阳极--直接水解法制得的纳米LiTi2O4粉体平均粒径在10-15mm左右。
“牺牲”阳极法制备纳米NiAl2O4的方法与制备LiTi2O4相似，经溶胶-凝胶(Sol-gel)过程制得纳米NiAl2O4。水解粉体在350oC煅烧2h,采用红外（IR）、差热-热重分析（TG-DTA）、X-射线衍射（XRD）、电子透射技术（TEM）等手段对前驱体和纳米NiAl2O4进行了表征。结果表明，电解法可以在低温下制备得到纳米NiAl2O4粉体，粉体具有一定的热稳定性，呈单分散结构，平均粒径在10-20nm之间。为超纯纳米材料的制备提供了一条新途径。
The electro-synthesis of metal alkoxide used pure metal as sacrificial anode and inertia electrode as cathode. Current passed through the absolute alcohol solution with the electro-conductive additive, and metal anode was dissolved and reducing reaction occurred on cathode. The Sol-gel process, which was based on the hydrolysis and condensation of metal alkoxide, could synthesize nanometer material with a special structure , high purity and well-proportioned granularity at a low temperature.
In this paper, the organic ammonium was used as electro-conductive additive. 3.5g lithium slice was added in the ethanol and acetyl-acetone solution, and then the precursor of the nano-LiTi2O4 powder was synthesized by anodic dissolution of titanium at the current of 0.2A for 4h. Nano-LiTi2O4 powder was prepared for by a direct sol-gel process of the electrolyte solution and calcining at the temperature of 4500C for 2h. IR. spectrum, TG-DTA, XRD, and TEM were used to investigate the structure of the precursor and the nano- LiTi2O4 powder. The result showed that the nano-sized LiTi2O4 with a narrow distribution of 10-15 nm was obtained by the electrochemical dissolution following hydrolysis.
The measure, by which nano-NiAl2O4 was synthesized, is similar with that of LiTi2O4 . Nano-sized NiAl2O4 was prepared for by a direct sol-gel process of the electrolyte solution. The structures of the precursor and its nano-sized powder were investigated by IR. spectrum ,TG-DTA, XRD, and TEM. The experiment showed that nano-sized NiAl2O4 with a narrow distribution of 10-20 nm was obtained at a low temperature of 3500C, and it possessed a certain heat stability and a disperse structure. This process may be recommended as a promising method to synthesize other composite nano-powders.
引文
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Jaumier P., Jousscaume B. New route to monoorganotin oxides and alkoxides from
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[22] Bing C., Tang Y.X. Synhesis and hydrolysis of hybridiaed silicon alkoxide: Si(OEt)x(OBut)4-x Part Ⅰ: Synthesis and identification of the Si(OEt)x(OBut)4-x [J]. Journal of Sol-gel Science and Technology, 1997,10:247-253.
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[29] Boulmaaz S., Papiernik R., Hubert-Pfalzgraf L.G., et al. Chemical routes to oxides: alkoxide vs. alkoxide-acetate routes: synthesis, characterization, reactivity and polycondensation of MNb2(OAc)2 (OPri )10 (M=Mg, Cd, Pb) species[J]. J. Mater Chem., 1997,7(10): 2053-2061.
[30] Methrotra R.C., Singh A. Chemistry of oxo-alkoxides of metals[J]. Chemical Society Reviews, 1996:1-13.
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[33] 杨南如,佘桂郁. 溶胶凝胶法的基本原理与过程[J]. 硅酸盐通报, 1992,2:56-60.
[34] Whitmire K.H. Perspectives on bismuth alkoxide chemistry and its relation to bismuth-oxide-based materials and catalysts[J]. Chemtracts-Inorganic Chemistry, 1995,7:167-181.
[35] Bing C., Tang Y.X. Synhesis and hydrolysis of hybridiaed silicon alkoxide: Si(OEt)x(OBut)4-x Part Ⅱ: Hydrolysis of the Si(OEt)x (OBut)4-x [J]. Journal of Sol-gel Science and Technology, 1997,10: 255-261.
[36] Narala C.K., Weber W. Incorporation of lanthanides in alumina matrices by a sol-gel process employing heterometallic alkoxides, M[Al(OPri)4]3, as precursor[J]. J. Mater Chem., 1997,7(9):1821-1829.
[37] Hoebbel D., Veinert T. On the hydrolytic stability of organic ligands in Al-, Ti- and Zr- alkoxides complexes[J]. Journal of Sol-gel Science and Technology, 1997,4(1):38-42.
孙刚,杨森,张祖德. 新颖的玻璃制备方法-溶胶-凝胶法[J]. 化学通报,
[38] 1990,11:45-51.
[39] Barthez J.M. Hydrolysis and condensation of transition metal alkoxide: Experiments and simulations[J]. Journal of Sol-gel Science and Technology, 1997,8:83-88.
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[41] 曾庆冰, 李效东, 陆逸. 溶胶-凝胶法基本原理及其在陶瓷材料中的应用[J]. 高分子材料科学与工程, 1998,14(2):138-143.
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[2] 褚道葆. 有机电化学概论. 1996:P2-4.
[3] 陈敏元. 有机电化学的新进展[J]. 精细化工, 2000,17(Suppl.):1-3.
[4] 乌居滋. 近代有机电化学的动向和未来(三). 陈敏元译. 云南工学院出版社, 1985:P1-4.
[5] 王光信,张积树.有机电合成导论.化学工业出版社, 1997:P1-3.
[6] 陈敏元. L-半胱氨酸盐酸水合物电解还原合成的研究[J]. 化学试剂, 1983,5(3):23-26.
[7] 闵恩泽,傅军. 绿色化学的进展[J]. 化学通报, 1999,1:10-15.
[8] 陈明文. 清洁生产-环境战略的新认识[J]. 化学进展, 1998,10(2): 113-122.
[9] 白春礼. 中国化学的发展与展望[J]. 大学化学, 2000,2:1-10.
[10] 黄培强, 高景星. 绿色合成:一个逐渐形成的科学前沿[J]. 化学进展, 1998, 3:265-272.
[11] 陈敏元.有机电化学将成为21世纪的热门学科[J].化工时刊, 1999, 13(5):40-43.
[12] 丁邵民,王继东,宋华付. 消耗电极法在有机电合成中的应用[J]. 精细化工, 2000,17 (Suppl.):7-9.
[13] Utley J. Trends in organic electrosynthesis[J]. Chemical Society Review, 1997,26: 157-167.
[14] 王大全. 面向21世纪的中国精细化工[J]. 广东化工, 1998, 6: 5-8.
[15] 孙世刚. 未来科学和技术的电化学-第49届国际电化学年会有机电化学简介 [J]. 精细化工, 1998,15(6):24-26.
[16] Veith M., Mathur S., Mathur C. New perspectives in the tailoring of hetero(bi- and tri-)metallic alkoxide derivatives[J]. Polyhedron, 1998, 17(5-6): 1005-1034.
[17] Rath S.P., Mondal S., Chakravorty A. Chemistry of hydrazonato oxovanadium(Ⅴ) alkoxides derived from dihydric/monohydric alcohols[J]. Inorganica Chimica Acta., 1997,263:247-253.
Jaumier P., Jousscaume B. New route to monoorganotin oxides and alkoxides from
[18] trialkynyloganotins[J]. Chem.Commun., 1998: 369-370.
[19] Camail M., Humbert M., Margaillan A. et al. New acrylic titanium polymers: 1.Synthesis and characterisation of new titanium trialkoxide methacrylate monomers prepared via the esterification of methacrylic acid by titanium tetraalkoxides[J]. Polymer, 1998, 39(25): 6525-6531.
[20] Kim J.Y., Sriram M.A. New molecular precursors from the reaction of hydrazine and aluminum alkoxide for the synthesis of powders in the Al-O-N system[J]. The Journal of Physical Chemistry B, 1997,101(24):4689-4696.
[21] Veith M., Mathur S. Novel ionogenic heterometal alkoxide derivatives[J]. Chem.Commun., 1997:2197-2198.
[22] Bing C., Tang Y.X. Synhesis and hydrolysis of hybridiaed silicon alkoxide: Si(OEt)x(OBut)4-x Part Ⅰ: Synthesis and identification of the Si(OEt)x(OBut)4-x [J]. Journal of Sol-gel Science and Technology, 1997,10:247-253.
[23] Hindle N.J., Hall C.D. Kinetics and mechanism of the formation of mono- and di- phthalate esters catalysed by titanium and tin alkoixdes[J]. J.Chem.Soc., Perkin Trans., 1998,2:1249-1254.
[24] Turova N. Ya., Turevskaya E. P., Yanovskaya M. I., et al. Physicochemical approach to the studies of metal alkoxides[J]. Polyhedron,1998,17(5-6):899-915.
[25] Starikova Z. A., Yanovsky A. I., Kotova N.M., et al. Synthesis and crystal structure of the double barium-titanium methoxide [Ba2Ti4O(Ome)18(MeOH)7]·MeOH[J]. Polyhedron, 1997, 16(24): 4347-4351.
[26] Boyle T.J., Alam T.M., Dimos D., et al. Niobium(Ⅴ) alkoxides. Synthesis, structure, and characterization of [Nb(μ-OCH2CH3) (OCH2C(CH3)3)4]2,﹛[H3CC(CH2O) (CH2-μ-O)(C(O)2)] Nb2(μ-O)(OCH2CH3)5﹜2, and ﹛[H3CC(CH2O)2(CH2-μ-O)]Nb (OCH2CH3)2﹜2 for production of mixed metal oxide thin films[J]. Chem.Mater., 1997,9:3187-3198.
[27] Goel S.C., Kramer K.S. Preparation and X-ray crystal structures of volatile copper(Ⅱ) alkoxides[J]. Polyhedron, 1990,9(4):611-613.
[28] Gall F.L., Biani F.F.d., Caneschi A., et al. Synthesis, crystal structures and magnetic characterization of four β-diketonate -alkoxide iron(Ⅲ) dimers. Dependence of the magnetic properties on geometrical and electronic parameters[J]. Inorganic Chimica Acta, 1997,262:123-132.
[29] Boulmaaz S., Papiernik R., Hubert-Pfalzgraf L.G., et al. Chemical routes to oxides: alkoxide vs. alkoxide-acetate routes: synthesis, characterization, reactivity and polycondensation of MNb2(OAc)2 (OPri )10 (M=Mg, Cd, Pb) species[J]. J. Mater Chem., 1997,7(10): 2053-2061.
[30] Methrotra R.C., Singh A. Chemistry of oxo-alkoxides of metals[J]. Chemical Society Reviews, 1996:1-13.
[31] Bradley D.C. Metal alkoxides as precursors for electronic and ceramic materials[J]. Chem.Rev., 1989,89:1317-1322.
[32] K.G. CAULTON and L.G. HUBERT-PFALZGRAF. Synthesis, Structural Principles, and Reactivity of Heterometallic Alkoxides. Chem. Rev.1900,90,969-995.
[33] 杨南如,佘桂郁. 溶胶凝胶法的基本原理与过程[J]. 硅酸盐通报, 1992,2:56-60.
[34] Whitmire K.H. Perspectives on bismuth alkoxide chemistry and its relation to bismuth-oxide-based materials and catalysts[J]. Chemtracts-Inorganic Chemistry, 1995,7:167-181.
[35] Bing C., Tang Y.X. Synhesis and hydrolysis of hybridiaed silicon alkoxide: Si(OEt)x(OBut)4-x Part Ⅱ: Hydrolysis of the Si(OEt)x (OBut)4-x [J]. Journal of Sol-gel Science and Technology, 1997,10: 255-261.
[36] Narala C.K., Weber W. Incorporation of lanthanides in alumina matrices by a sol-gel process employing heterometallic alkoxides, M[Al(OPri)4]3, as precursor[J]. J. Mater Chem., 1997,7(9):1821-1829.
[37] Hoebbel D., Veinert T. On the hydrolytic stability of organic ligands in Al-, Ti- and Zr- alkoxides complexes[J]. Journal of Sol-gel Science and Technology, 1997,4(1):38-42.
孙刚,杨森,张祖德. 新颖的玻璃制备方法-溶胶-凝胶法[J]. 化学通报,
[38] 1990,11:45-51.
[39] Barthez J.M. Hydrolysis and condensation of transition metal alkoxide: Experiments and simulations[J]. Journal of Sol-gel Science and Technology, 1997,8:83-88.
[40] Sayilkan H. New metal alkoxides: Synthesis and hydrolysis -condensation reactions; some adsorption features of the hydrolysis -condensation products[J]. Journal of Materials Science, 1999, 34: 5325-5330.
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