钙钛矿型复合氧化物纳米晶的合成、表征及其催化性质研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
本论文致力于钙钛矿结构的掺杂镁的钴酸镧以及铁酸铋复合氧化物的合成、表征与其催化性质研究。
     采用改进的柠檬酸溶胶-凝胶法合成出具有高比表面积的镁掺杂的钴酸镧可见光光催化剂的单分散体系并分别对其光催化氧化有机染料以及一氧化碳的完全氧化的气相小分子的催化反应活性进行了测试和研究。
     采用酒石酸复合物热解和熔盐中再生处理两步结合方法,得到了具有高活性铁酸铋复合氧化物可见光光催化剂,并对其光催化活性的影响因素进行了初步的研究与探讨。
     本论文对开辟与可见光相匹配的钙钛矿结构的复合氧化物光催化剂的研究与应用以及为开发利用绿色光源-太阳能的研究打下一定基础。
The properties of multicomponent perovskites are good in magnetism, electricity, optics, catalysis,sensor for gas detection and resistance to poisoning etal. They also have been entitled for almighty materials. The perovskite structure materials made of ABO_3(LaCoO_3,LaMnO_3,LaFeO_3) have attracted considerable attention in the field of material and catalysis for their good catalytic oxidation activities for catalytic oxidation little molecule(CH_4、CO、NO_x). SrTiO_3, LaCoO_3, LaFeO_3, BiFeO_3 are also of good photo-catalytic activities. The bandgap energy(eg) values of LaCoO_3, LaFeO_3 and BiFeO_3 are lower and this results in their absorbance to visible-light. So these perovskite materials are catalysts to be friendly for environment. In this paper, the improved sol-gel method and the pyrogenation of oxalate combined to melt salt method are used to prepare the Mg-doped LaCoO_3 and BiFeO_3 catalysts. The properties of materials lie on the method of preparation. The syntheses for multi-component perovskite include mainly the high temperature solid state reactions between oxides and/or carbonate precursors, hydrothermal method, sol-gel method, pyrogenation method, co- precipitation and high energy mechanical mill method(HEM). Generally, the High activities catalysts should be of high BET, well dispersivity and good surface crystalline etc.
     In above mentioned methods, the relatively high temperature results in the decreasing in BET, the severe agglomerate and the bad inhomogeneous in size in methods of high temperature solid state reactions, pyrogenation method and co- precipitation.
     The samples with high dispersivity obtained by hydrothermal method and high energy mechanical mill method because of the relatively low temperatures which favors the formation of low agglomeration and homogeneity. But the thermal stability obtained by the high energy mechanical mill method is poor that in the application in high temperature as a catalyst will decrease rapidly in BET. The particles obtained from the hydrothermal method possess of well dispersivity and good surface crystalline. But the sizes are very large to lead to the low in BET. The sol-gel method possess of many advantages in preparation catalysts of high activities. In its initial stage, precursors are controlled by adding chelating agent to slow the hydrolytic rate of ion and mix well even in the molecule level. The temperature is low for form the final product .The size is little and the sample obtained by sol-gel method is pure and well in dispersivity. So the sol-gel process is favorable for synthesize the perovskite materials with catalytic property.
     Semiconductors with heterogeneous photocatalytic behavior have attracted considerable attention due to the possible applications in environmental amelioration and solar energy utilization. LaCoO_3 solid with perovskite structure is a good material in electrics and catalysis. LaCoO_3 is a semiconductor at room temperature and its bandgap is about 0.6eg. So its absorbance corresponds well with visible–light .In this study, we focus on the improving in synthetic method to enhance the its BET and activities. In synthesis the perovskite structure substance, the conventional sol-gel process actually has many advantages ,for example,the reaction carries out in lower temperature (about 600-700℃) and the purity of sample is high . but the agglomeration still exists arise from the calcination process in this method and the BET of sample is lower. Tnvestigators have made great efforts for increasing the BET and the reported specific surface area for LaCoO_3 is usually still less than 40 m~2/g. Dispersing nanoparticles in certain matrix during the calcination process is applied in preparing monodispersed nanoparticles with large surface area. Adding a small amount of a second inert phase such as Al2O_3 or SiO2 during the sol-gel manufacturing process is used to restrict the growth of nanocrystals, which is believed to result in tiny discrete particles of this phase located in the interface regions between the nanocrystals, but it is difficult to remove the inert phase. In this paper, we report the preparation of well-dispersed Mg-doped LaCoO_3 nanocrystals by a modified sol-gel method. Controllable particle size can be obtained by introduction excess magnesium nitrate into the reactant mixture. During the calcination process, a MgO phase serves as pinning particles to inhibit the growth and agglomeration of Mg-doped LaCoO_3 nanocrystals. After removing MgO by dissolving in diluted acetic acid, well dispersed Mg-doped LaCoO_3 nanocrystals with large surface is obtained and with the increasing of MgO content, the size of nanocrystals gradually decreases from 31.6 to 13.2nm and the BET value increases from 13.9 to 64.5m2/g. The photocatalytic activity, which is evaluated by measuring the decolorization ratios of Reactive Brilliant Red X-3B, is significantly enhanced with the well-dispersed Mg-doped LaCoO_3 nanocrystals. The photocatalytic activity is related to the crystal size and specific surface area.
     BiFeO_3 is of simple perovskite-structure. It is typical ferroelectric materials and antiferromagnetic materials. Curie temperature(Tc)is 1110K and Nier temperature (Tn)is 650K. At present, the reports on the BiFeO_3 locus on the study of ferroelectric film applying in semiconductor memorizer. The reports on optical property of this materials is few. JunHua Luo reported the SrTiO_3/BiFeO_3–Fe2O_3 photo-catalytic materials with shell-core structure. The BiFeO_3 is a visible-light sensitizer and the bandgap is 2.1eV corresponding to the absorbance of 590nm photons.
     The reports on low temperature synthetic methods of BiFeO_3 mainly include the pyrogenation of oxalate and tartaric acid complex. The carrying temperature in two methods is all about 650℃.The photocatalytic-activities of samples obtained from the above methods is almost consistent. In order to enhance the photocatalytic-activities of samples, BiFeO_3 and LiNO_3 are mixed well by milling the mixture. Then the mixure is heated at the melting point of the LiNO_3 for some time ,following by washing the mixture to remove the LiNO_3. The study show that the photo-catalytic activities of BiFeO_3 samples enhance greatly after crystallization in melting salt. Experiment shows that the photo-catalytic activities of BiFeO_3 samples are affected by ratios of LiNO_3 to BiFeO_3 and crystallization time in melting salt. There is not any report on the photo-catalytic activities of BiFeO_3 which is developed in melting salt up to now.
引文
1. C. Jifield, W. R. Scott, J. Solid State Chem, 10, 183(1974)
    2. 刘守新,刘鸿,光催化及光电催化基础与应用,第七章,化学工业出版社, 2006
    3. Blake, M. Daniel, NREL/TP- 430 - 6084, national Renewal Energy Laboratory, Golden, Co (1994)
    4. Blake, M. Daniel, NREL/TP- 340 - 22197, national Renewal Energy Laboratory, Golden, Co (1997)
    5. Blake, M. Daniel, NREL/TP – 570 - 26797, national Renewal Energy Laboratory, Golden, Co (1999)
    6. Blake, M. Daniel, NREL/TP - 640 - 28297, national Renewal Energy Laboratory, Golden, Co, 2002
    7. 冷文华,张莉,成少安等,环境科学,6,46(2000)
    8. R. Franke,C. Franke,Chemosphere,39(6):2651(1999)
    9. H. Hidaka,S. Horikoshi,K. Ajisaka et al,J Photochem Photobiol A,
    108(2),197(1997)
    10. 葛飞等,中国给水排水,17(10):9(2001)
    11. C. W. Berry, T. J. Moore, J .A Safar, Implant Dent (BPT), 1(1), 59 (1992)
    12. 朱春娟, 陈双全, 杨曦等, 环境科学, 18(4) : 30 (1998)
    13. S. Yamazaki, H. Tsukamoto, k. Arikik et al, Applied Catalysis B: Environmental,33(2): 09 (2000)
    14. W. Choi, J. Y. Ko, H. Park et al, Applied Catalysis B: Environmental,31(3), 209 (2001)
    15. J. Shang, Y. G. Du, Z. L. Xu, Chemosphere, 46(1): 93 (2002)
    16. H. Einga, S. Futamura, T. Ibusuki, Applied Catalysis B: Environmental,38(3), 215 (2002)
    17. A.V. Vorontsov, Applied Catalysis B: Environmental,32(1~2):11 (2001)
    18. R. M. Alberici, M. c. Canela, Applied Catalysis B: Environmental, 30(3~4): 387 (2001)
    19. E. Campagnoli,A. Tavares,L. Fabbrini et al, Applied Catalysis B: Environmental, 55,133 (2005).
    20. J. S. Kang,H. Han,B .W.Lee,C. G. Olson et al.,Phys.Rev.B. 64,024429(2001)
    21. M. Kawasaki.,Proceeding of the First Symposium on Atomic-scale Surface and Interface Dyamic[B] Surface and interface issues in the heteroepitaxy of high Tc superconducting thin films March 13-14 ,Tokyo(1997).
    22. 王颖霞, 别利剑, 秦瑞雯, 林建华, 尤力平,自然科学进展,12 (5),449(2002)
    23. S .Royer,F. Bérubé,S .Kaliaguine.,Applied Catalysis A: General, 282 ,273(2005)
    24. 傅希贤,杨秋华,王俊珍等,中国稀土学报,20(6),589(2002).
    25. S. Nakayama,M. Okazak,Y. L. Aung et al., Solid State Ionics,158,133(2003)
    26. K. Sreedhar,N. R. Pavaskar ,Materials Letters,53,452(2002)
    27. J. S.Wang,S. Yin,Q. W. Zhang,F. Saito,Solid state Ionics,172,191(2004)
    28. 10 H. Taguchi,S.Yamada,M. Nagao,Y. Ichikawa et al, Materials Research Bulletin,37,69(2002)
    29. X. W. Wang,Z. Y. Zhang, S. X.Zhou ,Materials Sience and Engineering:B,86, 29(2001)
    30. H. J,.wang,M. Awano.,Journal of the European Ceramic Society, 21,2103(2001).
    31. X .X. Fu,Q. H.Yang,J. Z. Wang et al. Jourmal of Rare Earths, 21(4),424(2003).
    32. S. Royer,H. Alamdari,D. Duprez,S. Kaliaguine, Applied Catalysis B: Environmental, 58,273(2005)
    33. T. Ito,Q. W. Zhang,F. Saito,Power Technology,143-144,170(2004).
    34. G.. Xiong, X. Wang. L .D. Lu, X. J. Yang, J. Solid State Chem, 141, 70(1998)
    35. X. H. Liu, H. L. Wang, D. Y. Chen, Y. Wang et al, J. Appl. Polym. Sci, 73, 2569(1999)
    36. S. Kaliaguine ,A. Van Neste,V. Szabo,J. E. Gallot et al, Applied Catalysis A: General, 2001, 209: 345-358.
    37. B. D. Stojanovic, Journal of Materials Processing Technology,143-144: 78(2003 )
    38. #18. D. Zh,H. Zhu Zhang and Hang Y H.,J. Phys: Condens. Matter,14, L519(2002).
    39. J. Y Choi,C. H. Kim,D. K. Kim.,Journal of the American Ceramic Society 81(5): 1353 (1998),。
    40. J. H. Luo,P. A. Maggard, Adv. Mater. 18,514(2006).
    41. 桑丽霞,傅希贤,白树林,杨秋华等,催化工业与工程, 17(6):33(2000).
    42. K. D. Mandal, L. Behera, K. Ismail, Journal of Alloys and Compound,325, L17(2001)
    43. Y. X. Zhang, Y. F. Zhu,R. Q. Tan et al. Thin Solid Film,388,160(2001)
    44. J. Shu,S. Kaliaguine, Applied Catalysis B: Environmental,16,L303(1998)
    45. M. O’ Conell,A. K. Norman,C. F. Huttermann,M. A. Morris,Catal. Today,47 (1-4):123(1999)
    46. S. Royer, H. Alamdari,D. Duprez, S. Kaliaguine,Appl. Catal. B: Environ, 58,273(2005)
    47. H. Taguchi,S. Yamada,M. Nagao,Y. Ichikawa,K. Tabata, Mater. Res. Bull. 37,69 (2002)
    48. E. Campagnoli,A. Tavares, L. Fabbrini, I. Rossetti,Appl. Catal. B: Environ. 55,133 (2005).
    49. V. Szabo, M. Bassir, A. Van Neste, S. Kaliaguine, Appl. Catal. B: Environ. 37,175(2002)
    50. M. A. Pena and J. L.G. Ferro, Chem. ReV. 101,1981(2001)
    51. T. Kida,G. Guan, A. Yoshida,Chemical Physics Letters,371,563 (2003)
    52. Kudo,International Journal of Hydrogen Energy III(IIII)III-III, 04050:1-6(2005)
    53. N. Ramadass, J. Gopalakrishnan and M. V. C. Sastri, J. Less Common Metals 65(1), 129(1979)
    1. D.B. Meadowcroft, Nature 226,847(1970).
    2. S. Ajamia, Y. Mortazavia, A. Khodadadia, F.Pourfayaza, S.Mohajerzai, Sensors and Actuators B. 117,420 (2006)
    3. R. Leanza, I. Rossetti, L. Fabbrini, C. Oliva, L.Forni, Appl. Catal. B. 28,55(2000)
    4. P. Ciambelli, S. Cimno, S. De Rossi, L. Lisi, G. Minelli, P. Porta, G. Russo. Appl. Catal. B. 29,239(2001)
    5. E. Campagnoli, A. Tavares, L. Fabbrini, I. Rossetti, Appl. Catal. B: Environ. 55,133(2005)
    6. P. Ciambelli, S. Cimno, S. De Rossi, L. Lisi, G.Minelli, P. Porta, G. Russo. Appl. Catal. B. 29,239(2001)
    7. K. Barbara, T. Wlodzimierz, Catal. Today. 90,121(2004)
    8. M. Alifanti, N. Blangenois, M. Florea, B. Delmon, Appl. Catal. A. General.
    280,255 (2005)
    9. S.Colonna, S. De Rossi, M. Faticanti, I. Pettiti, P. Porta, Journal of Molecular Catalysis A: Chemical 180, 161(2002)
    10. R. Spinicci, A.tofanari, A Delmastro, D. Mazza, S. Ronchetti, Mater. Chem and Phys 76, 20(2002)
    11. S. H. Lee, J. Y. Lee. Y, M. Park, J. H.Wee, K.Y. Lee, Catal. Today. 117,376(2006)
    12. P. Salomonsson, T. Griffin, B. Kaasemo, Appl. Catal A General. 104,175(1993).
    13. I. Pettiti, S. Colonna, S. De Rossi, M Faticanti, G. Minellia and P. Portaa, Phys.Chem.Chem.Phys. 6, 1350(2004)
    14. M. A. Pena and J. L.G. Ferro, Chem. ReV. 101,1981(2001)
    15. M. A. Fox, M. T. Dulay, Chem. Rev. 93,341(1993)
    16. M. R. Hoffmann, S. T. Martin, W. Choi, D. W. Bahnemann, Chem. Rev. 95, 69(1995)
    17. Pirkanniemi, M. Sillanpaa, Chemosphere 48,1047(2002)
    18. K. I. Hadjiivanov, D. G. Klissurski, Chem. Soc. Rev. 25(1):61(1996)
    19. A. L. Linsebigler, G. Lu, J. T. Yates, Jr., Chem. Rev. 95(3):735(1995)
    20. R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, Y. Taga, Science 293,269(2001)
    21. 王俊珍,傅希贤, 杨秋华等,应用化学,16(3):97(1999)
    22. P. Porta, S. De Rossi, M. Faticanti, G. Minelli, I. Pettiti, L. Lisi, M. Turco, J. Solid State Chem. 146, 291 (1999)
    23. D. Berger, V. Fruth, I, Jitaru, J. Schoonman, Mater. Letters 58 , 2418(2004)
    24. J. Shu, S. Kaliaguine, Appl. Catal. B: Environ. 16, L303(1998)
    25. N. Ramadass, J. Gopalakrishnan, and M. V. C. Sastri, J. Less Common Metals 65(1):129 (1979)
    26. J. G. Li, X. L. Kou, Y. Q, H. Y. He, Phys. Stat. sol. (a). 191,255 (2002)
    27. H. Taguchi, S. Yamada, M. Nagao, Y. Ichikawa, K. Tabata, Mater. Res. Bull. 37,69(2002)
    28. L. Lisi, G. Bagnasco, P. Ciambelli, S. De Rossi, P. Porta, G. Russo, M. Turco, Journal of Solid State Chemistry,146,176(1999)
    1. S. Ajamia, Y. Mortazavia, A. Khodadadia, F.Pourfayaza, S.Mohajerzai, Sensors and Actuators B. 117,420 (2006)
    2. R. Leanza, I. Rossetti, L. Fabbrini, C. Oliva, L.Forni, Appl. Catal. B. 28,55(2000)
    3. P. Ciambelli, S. Cimno, S. De Rossi, L. Lisi, G. Minelli, P. Porta, G. Russo. Appl. Catal. B. 29,239(2001)
    4. P. Ciambelli, S. Cimno, S. De Rossi, L. Lisi, G.Minelli, P. Porta, G. Russo. Appl. Catal. B. 29,239(2001)
    5. K. Barbara, T. Wlodzimierz, Catal. Today. 90,121(2004)
    6. M. Alifanti, N. Blangenois, M. Florea, B. Delmon, Appl. Catal. A. General. 280,255 (2005)
    7. S.Colonna, S. De Rossi, M. Faticanti, I. Pettiti, P. Porta, Journal of Molecular Catalysis A: Chemical 180, 161(2002)
    8. R. Spinicci, A.tofanari, A Delmastro, D. Mazza, S. Ronchetti, Mater. Chem and Phys 76, 20(2002)
    9. S. H. Lee, J. Y. Lee. Y, M. Park, J. H.Wee, K.Y. Lee, Catal. Today. 117,376(2006)
    10. P. Salomonsson, T. Griffin, B. Kaasemo, Appl. Catal A General. 104,175(1993).
    11. (14)I. Pettiti, S. Colonna, S. De Rossi, M Faticanti, G. Minellia and P. Portaa, Phys.Chem.Chem.Phys. 6, 1350(2004)
    12. X .X. Fu,Q. H.Yang,J. Z. Wang et al. Jourmal of Rare Earths, 21(4),424(2003).
    13. T. Kida,G. Guan, A. Yoshida,Chemical Physics Letters,371,563 (2003)
    14. 王俊珍,古凤才,颜秀茹,王建苹等,应用化学,12(6):29(1995)
    15. A. Kudo,International Journal of Hydrogen Energy III(IIII)III-III, 04050:1-6(2005)
    16. J. H. Luo,P. A. Maggard, Adv. Mater. 18,514(2006)
    17. C. Ederer and N. A. Spaldin, Phys. Rev. B,71, 224103(2005)
    18. Y. Wang , Q. H.. Jiang , H. C. He and C. W. Nan, Applied Physics Letters, 88, 142503(2006)
    19. H. R. Liu , Z. L. Liu, Q. Liu and K.L. Yao, J. Phys. D: Appl. Phys. 39, 1022(2006)
    20. R. Mazumder, S. Ghosh, P. Mondal et al,Journal of Applied Physics, 100, 033908 (2006)

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700