摘要
氧化锰作为环境中重要的吸附载体、氧化还原载体、化学反应催化剂及信息载体,其资源属性和环境属性日益受到人们的关注,因此,促进氧化锰矿物资源的开发与利用具有重要的理论和实践意义。尤其是3×3隧道结构的钙锰矿,由于特殊的结构有利于金属离子的嵌入和脱出,使得其除了在氧化-还原、吸附-解吸方面的应用外,更可以作为离子交换材料、二次锂离子电池电极材料等应用于诸多领域。
本文通过改变前驱物的制备,在常压回流和热液高压条件下合成出了不同氧化度系列的钙锰矿—水锰矿混合物,探讨了改进后热液产物对重金属Cr(Ⅲ)的氧化特性和对Pb的吸附性能,以及作为锂离子电池正极材料的充放电性能。取得的主要结果有:
1、通过控制水钠锰矿合成过程中Mn(Ⅱ)和Mn(Ⅶ)的比例,获得了不同氧化度系列的前驱物,并通过对传统方法的改进,直接合成了不同氧化度系列结构稳定的布塞尔矿。
2、经常压回流和热液转化,获得了以钙锰矿为主的锰氧化物。传统方法获得的前驱物在转化的同时还存在部分水钠锰矿,改进方法合成的前驱物在向钙锰矿转化后,水钠锰矿完全消失,但同时出现了部分水锰矿杂质,结果显示,产物具有不同的锰平均氧化度。
3、上述获得的不同氧化度系列的钙锰矿—水锰矿产物对Cr(Ⅲ)表现出了不同的氧化特性,样品的氧化度越大,Cr(Ⅵ)的氧化量越高。
4、钙锰矿—水锰矿产物对Pb的吸附表现出了不同的性能:样品氧化度越高,对Pb吸附量越大,在吸附过程中释放的Mn(Ⅱ)也越少;而释放的H~+则随氧化度的升高有所上升,释放的Mg~(2+)与样品氧化度无明显关系。
5、不同氧化度系列产物作为锂离子电池正极材料,表现出了不同的充放电性能:氧化度3.46~3.73之间的样品显示出了较高的首次放电比容量,氧化度为3.83的样品在首次放电比容量较小的情况下,表现出了较高的循环稳定性,经40次充放电后,其容量保持率最高,仍然达到79%。
Mn oxide minerals are known as important adsorbents,redox agents,catalysts and environmental information carriers in soils,and their resource and environmental properties have been attracting more and more researchers' concern. Therefore,it is of great significance to promote exploration and utilization of Mn oxide minerals.Yodorokite is one important mineral of them for its 3×3 tunnel structural which is propitious to let the metal ion insert and emerge,and this outstanding property makes it is largely applied not only as oxide-redox and adsorbent,but also as the material for ion-change and electrode of lithium batteries.
Based on the todorokite successfully obtained at atmospheric pressure and high pressure,we used general techniques to analyze the similarities and differences of the products synthesized in these two diverse methods.Meanwhile,the characteristics of oxidation of Cr and adsorption of Pb by amendable products were observed under experimental condition,as well as its chargeable and dischargeable capability as electrode of lithium batteries had been understood.The results are as follows:
1、To obtain a series of products with different Mn AOS,we controlled the proportion of Mn(Ⅱ) and Mn(Ⅳ) in the precursor-birnessite,and via improve the traditional method,we got buserites with steady frame and different Mn AOS.
2、By the method of synthesized at atmospheric pressure and high pressure,we got the Mn oxides which were mainly composed with todorokite.It was testified that birnessite was still remain in the products by traditional method,while it disappeared through the improved way,but some manganite was observed.Testing results identified that the products presented big Mn AOS differences.
3、The products of todorokite-manganite with different Mn AOS presented variable oxidation property that was the sample with higher AOS had greater rate of oxidation of Cr(Ⅲ).
4、The adsorption to Pb by the todorokite-manganite samples revealed different capability.The higher Mn AOS sample has a greater sorbed capability but lower Mn(Ⅱ) release ability during the adsorption process,and the release amount of H~+ rose when AOS went up,but the release amount of Mg had no remarkable relationship with AOS.
5、The samples with different AOS as lithium electrode also revealed different chargeable and dischargeable capability It was noticeable that the samples with AOS between 3.46 to 3.73 demonstrated high capability in the first discharge,while the mineral with AOS 3.83 displayed lesser capability in the first discharge,but its cycles were excellent,the capability still remained about 79%after 40 times of charge and discharge cycles.
引文
1.陈红,方土.用MnO_2氧化废水中As(Ⅲ)为As(Ⅴ)的特性.高等学校工程学报,2000,14(1):48-52
2.陈英旭,朱祖祥,何增耀.环境中氧化锰对Cr(Ⅲ)氧化机理的研究.环境科学学报,1993,13(1):45-50
3.董长勋,兰叶青,潘根兴.几种晶形氧化锰对Cr(Ⅲ)氧化作用的研究.哈尔滨商业大学学报(自然科学版)2006,22(6):44-17
4.樊耀亭,吕秉玲,徐杰,蒋永贵,张琳萍.水溶液中二氧化锰对铀的吸附环境.科学学报,1999,19(1):42-46
5.冯雄汉,刘凡,谭文峰,王贻俊,刘祥文.碱性介质中合成水钠锰矿的几个影响因素.地球化学,2002,31(5):495-500
6.冯雄汉,刘凡,谭文峰,刘详文,胡红青.回流条件下钙锰矿的合成及其初步表征.中国科学(D辑),2003,33(11):1084-1093
7.冯雄汉,谭文峰,刘凡,许永胜,王贻俊.热液条件下钙锰矿的合成及其影响因素.地球科学,2005a,30:347-352
8.冯雄汉,谭文峰,刘凡,黄巧云,刘详文.碱性介质中水钠锰矿的生成途径.中国科学(D辑),2005b,35(4):340-351
9.刘斌,夏熙.含钙、含钡和含镍钡镁锰矿的合成及在水溶液中电化学性能.应用科学学报,2001,19(2):185-188
10.刘凡,谭文峰,王贻俊.土壤中氧化锰矿物的类型及其与土壤环境条件的关系.土壤通报,2002a,33(3):175-180
11.刘凡,谭文峰,刘桂秋,李学垣,贺纪正.几种土壤中铁锰结核的重金属离子吸附与锰矿物类型,士壤学报,2002b,39(5):699-706
12.刘桂秋,冯雄汉,谭文峰,刘凡.几种土壤铁锰结核对Cr(Ⅲ)的氧化动力学特性.华中农业大学学报,2002b,21(5):450-454
13.刘桂秋,刘凡,谭文峰.几种土壤锰结核对Cr(Ⅲ)的氧化与锰矿物类型.土壤与环境,2002a,11(3):241-244
14.刘桂秋,谭文峰,冯雄汉,刘凡.几种土壤铁锰结核对Cr(Ⅲ)的氧化特性:Ⅱ pH、离子强度、温度等因素的影响。土壤学报,2003,40(6):852-857
15.刘粤惠,刘平安.X射线衍射分析原理与应用.北京:化学工业出版社,2003.122-139
16.刘铮.土壤与植物中锰的研究进展.土壤学进展.1991,19(6):1-10
17.鲁安怀,卢晓英,任子平,韩丽荣,方勤方,张琳萍.天然铁锰氧化物及氢氧化物环境矿物学研究.地学前缘,2000,7(2):473-483
18.鲁安怀.矿物学研究从资源属性到环境属性的发展.高校地质学报,2000,6(2):245-251
19.潘根兴.淮北土壤铁锰结核中过渡金属元素的富集及其环境地球化学意义.科学通报,1989,34(19):1505-1507
20.钱江初.1nm矿相结构稳定性的研究.海洋学报,1998,20(3):56-63
21.冉勇,刘铮.土壤和氧化物对稀土元素的专性吸附及其机理.科学通报,1992,18:1705-1709
22.谭文峰,李永华,刘凡,李学垣.湖北省几种土壤铁锰结核中的锰矿物类型.华中农业大学学报,1998,28:42-47
23.谭文峰,刘凡,李永华,贺纪正,李学垣.土壤铁锰结核中锰矿物类型鉴定的探讨.矿物学报.2000a.20:63-67.
24.谭文峰,刘凡,李永华,贺纪正,李学垣.我国几种土壤铁锰结核中的锰矿物类型.土壤学报,2000b,37(2):192-201
25.谭文峰,刘凡,李学垣.几种土壤铁锰结核对Cr(Ⅲ)的氧化特性(Ⅰ)——氧化锰矿物类型与吸附态离子的影响.环境科学学报,2001,21(5):592-596
26.吴巧玲,孙尧俊,黄月芳,费伦,龙英才.镁离子型Birnessite的合成和表征.分析测试学报,1998,17(2):20-23
27.夏熙,刘斌.钡镁锰矿合成及在水溶液中电化学性质研究.无机材料学报,2000,15(4):636-640
28.谢正苗,朱祖祥,袁可能,黄昌勇.土壤中二氧化锰对As(Ⅲ)的氧化及其意义.环境化学,1989,8(2):1-6
29.熊毅等编著.土壤胶体(第一册).北京:科学出版社,1983
30.熊毅等编著.土壤胶体(第二册).北京:科学出版社,1985
31.熊毅,陈家坊等编著.土壤胶体(第三册).北京:科学出版社,1990
32.杨勇,舒东,余海,夏熙,林祖赓.大隧道结构锂锰氧化物电极材料研究.电源技术,1997,21(5):190-199
33.于大仁,季国亮,丁昌璞等著.可变电荷土壤的电化学.北京:科学出版社,1996
34.章长江,孙尧俊,黄月芳.Mn型分子筛的合成与表征.复旦学报(自然科学版),1999,38(6):673-680
35.赵其国.21世纪土壤科学展望.地球科学进展,2001,16(5):704-709
36.赵其国.发展与创新现代土壤科学.土壤学报,2003,40(5):321-327
37.Ali A A,Al-Sagheer F A,Zaki M I.Surface texture morphology and chemical composition of hydrothermally synthesized tunnel-structure manganese(Ⅳ) oxide.Int J Inorg Mater,2001,3:427-435
38.Balisterieri L S,Murray J W.The surface chemistry of δ-MnO_2 in major ion seawater.Geochim Cosmochim Acta,1982,46:1041-1052
39.Burns R G,Bums V M,Stockman H W.A review of the todorokite-buserite problem: Implications to the mineralogy of marine manganese nodules. Am Mimeral, 1983, 68: 972-980
40. Chen Y X, Chen Y Y, Lin Q, Hu Z Q, Hu H, Wu J Y. Factors affecting Cr(III) oxidation by manganese oxides. Pedosphere, 1997, 7(2): 185-192
41. Chukhrov F V, Gorshkov A I, Sivtsov A V. New data on natural todorkites. Nature, 1979, 278: 631-632
42. Cornell R M, and Giovanoli R. Transformation of hausmannite into birnessite in alkaline media. Clays Clay Miner, 1988, 36, 249-257
43. Duncan M J, Leroux F, Corbeit J M, Nazar L F. Todorokite as a Li insertion cathode: Comparison of a large tunnel framework "MnO_2" structure with its related layered structure. J Electrochem Soc, 1998, 145: 3746-3757
44. Driehaus W, Seith R, Jekel M. Oxidation of arsenate(III) with manganese oxides in water treatment. Water Res, 1995, 29: 297-305
45. Fendorf S E, Zasoski R J. Chromium(III) oxidation by δ-MnO_2: Characterization. Environ Sci Technol, 1992,26:79-85
46. Frondel C, Marvis U B, Ito J. New occurrence of todorokite. Am Mineral, 1960, 45: 1167-1173
47. Fu G, Allen H E, Cowan C E. Adsorption of cadmium and copper by manganese dioxide. Soil Sci, 1991, 152:72-81
48. Giovanoli R., Stahli E, Feitknecht W. Uber Oxidehydroxide des vierwertigen Mangans mit Schichtengitter. 1. Natriummangan(II, III)- manganat(IV). Helv Chim Acta, 1970a, 53: 209-220
49. Giovanoli R. Vernadite is random-stacked birnessite. Mineralium Deposita, 1980a, 15: 251-253
50. Golden D C, Chen C C, Dixon J B. Synthesis of Todorokite. Science. 1986a, 231: 717-719
51. Golden D C, Dixon J B, Chen C C. Ion exchange, thermal transformations, and oxidizing properties of birnessite. Clays Clay Miner, 1986b, 34: 511-520
52. Golden D C, Chen C C, Dixon J B. Transformation of birnessite to buserite, todorokite, and manganite under mild hydrothermal treatment. Clays Clay Miner. 1987, 35: 271-280
53. Kim J B, Dixon J B, Chusuei C C, Deng Y J. Oxidation of Chromium(III) to (VI) by Manganese Oxides. Soil Sci Soc Am J, 2002, 66, 306-315
54. Kumagai N, Komaba S, Abe K and Yashiro H. Synthesis of metal-doped todoroktie-type MnO_2 and its cathode characteristics for rechargeable lithium batteries. J Power Sources, 2005, 146:310-314
55. Liu Z H, Kang L, Ooi K, Makita Y and Feng Q. Studies on the formation of todorokite-type manganese oxide with different crystalline birnessitres by Mg~(2+)-templating reaction. J Colloid Interface Sci, 2005, 285: 239-246.
56. Loganathan P, Burau R G, Fuerstenau D W. Influence of pH on the sorption of Co~(2+), Zn~(2+) and Ca~(2+) by a hydrous manganese oxide. Soil Sci Soc. Am J, 1977, 41: 57-62
57. Luo J and Suib S L. Preparative parameters, magnesium effects, and anion effects in the crystallization of birnessites. J Phys Chem B, 1997, 101: 10403-10413
58. Malati M A, Sear A. Oxidations by manganese(III)-. Oxidation of chromium(III). Polyhedron, 1989,8: 1874-1875
59. McKenzie R M. Proton release during adsorption of heavy metal ions by a hydrous manganese dioxide. Geochim Cosmochim Acta, 1979,43: 1855-1857
60. Mellin T A, Lei G Stabilization of 10A-manganates by interlayer cations and hydrothermal treatment: implications for the mineralogy of marine manganese concretions. Mar Geol, 1993, 115:67-83
61. Morgan J J, Stumm W. Colloid-chemical properties of manganese dioxide. J Colloid Sci, 1964, 19:347-359
62. Murray J W. The surface chemistry of hydrous manganese dioxide. J Colloid Interf Sci, 1974, 46:357-371
63. Norvell W A. Inorganic reactions of manganese in soils. In: Graham R D, Hannam R J, Uren N C eds., Manganese in soils and plants. Dordrecht: Kluwer Academic Pub, 1988: 37-58
64. Ostwald J. Some observations on the chemical composition of todorokite. Miner Mag, 1986, 50: 336-40
65. Post J E, Bish D L. Rietveld refinement of the todorokite structure. Am Mineral, 1988, 73: 861-869
66. Post J E, Veblen D R. Crystal structure determination of synthetic sodium, magnesium, and potassium birnessite using TEM and the Rietveld method. Am Mineral, 1990, 75: 477-489
67. Post J E. Manganese oxide minerals: Crystal structures and economic and environmental dral molecular sieves: Preparation, characterization and application. Science, 1993, 260: 511-515
68. Post J E. Manganese oxide minerals: Crystal structures and economic and environmental significance. Proc Natl Acad Sci, 1999, 96: 3447-3454
69. Risser J A, Bailey G W. Spectroscopic study of surface redox reactions with manganese oxides. Soil Sci Soc Am J, 1992, 56: 82-86
70. Shen Y F, Zerger R P, Suib S L, McCurdy L, Potter D I, O'Yang C L . Manganese oxide octahedral molecular sieves: Preparation, characterization and application. Science, 1993, 260:511-515
71. Shen Y F, Suib S L, O'Yang C L. Effects of inoganic cation templates on octahedral molecular sieves of manganese oxide. J Am Chem Soc, 1994, 116: 11020-11029
72. Shindo H, Huang P M. Comparison of the influence of manganese(IV) and typrosinase on the formation of humic substances in the environment. Sci Total Environ, 1992, 117/118: 103-110
73. Siegel M D, Turner S. Crtstalline todorokite associated with biogenic debris in manganese nodules. Science, 1983, 219: 172-174
74. Silvester E J, Manceau A. The mechanism of chromium(III) oxidation by Na-buserite. J Phys Chem, 1995, 99: 16662-16772
75. Suib S L. Sorption,catalysis, and separation by design. Chem Innov , 2000, 30: 27
76. Tian Z R, Yin Y G, Suib S L. Effect of Mg~(2+) ions on the formation of todorokite type manganese oxide octahedral molecular sieves. Chem Mater, 1997b, 9: 1126-1133
77. Tu S, Racz G J, Goh T B. Transformations of synthetic birnessite as affected by pH and manganese concentration. Clays Clay Miner, 1994,42: 321-330
78. Turner S, Buseck P R. Manganese oxide tunnel structures and their intergrowths. Science, 1979,203:456-458
79. Turner S, Buseck P. Todorokies: A new family of naurally occuring mananese oxides. Science, 1981,212: 1024-1027
80. Weaver R M, Hochela M F, Ilton E S. Dynamic processes occurring at the Cr(III) interface: Simultaneous adsorption, microprecipitation, oxidation/reduction, and dissolution. Geochimica et Cosmochimica Acta, 2002, 66:4119-4132