化学溶液沉积法制备WO_3·2H_2O薄膜及其电致变色性能
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摘要
目的研究具有不同微观结构的WO_3·2H_2O薄膜的电致变色性能。方法采用化学溶液沉积法在FTO玻璃上制备WO_3·2H_2O薄膜,通过加入不同的形貌控制剂(柠檬酸或草酸铵),制备不同纳米结构的WO_3·2H_2O薄膜。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析薄膜的成分结构和微观形貌,利用紫外可见光分光光度计对薄膜在波长为200～1000nm范围内的透光性进行研究,并通过电化学工作站对薄膜进行电化学性能分析。结果采用柠檬酸作为形貌控制剂制备的WO_3·2H_2O薄膜的透光性高达82%左右,其在着色和褪色状态的透过率差值为36.2%。通过添加柠檬酸或草酸铵作为形貌控制剂制备的WO_3·2H_2O薄膜均呈现出纳米片状结构,纳米片的厚度分别为5～15 nm和50～60 nm,但是采用柠檬酸制备的WO_3·2H_2O具有较多的间隙和裂缝,使其表现出了较好的电致变色性能。结论具有间隙和裂缝的纳米WO_3·2H_2O薄膜增加了薄膜与电解质的接触面积,减少了离子扩散的路径距离,更小的纳米结构可以提供更多的化学活性位点,从而表现出较好的电致变色性能。
The work aims to study electrochromic properties of tungsten oxide dihydrate films with different microstructures. Tungsten oxide dihydrate films were prepared on FTO by chemical solution deposition method. Different nanostructured WO_3·2H_2O films were synthesized by adding different morphology control agents(citric acid or ammonium oxalate). The composition and microstructure of the films were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM).UV-visible spectrophotometer was used to study the transmittance of films with wave length within 200～1000 nm and electrochromic performance of the films was investigated by an electrochemical workstation. The transmittance of WO_3·2H_2O film prepared with citric acid as the morphology control agent reached 82%, and the transmittance difference of film in colored and faded state was 36.2%. The WO_3·2H_2O films prepared by adding citric acid or ammonium oxalate as the morphology control agent exhibited nano-sheet structure. The thickness of the nanosheets was 5～15 nm and 50～60 nm, respectively. However,WO_3·2H_2O prepared with citric acid had more gaps and cracks, which exhibited better electrochromic properties. WO_3·2H_2O film with gaps and cracks increases the contact area between the film and the electrolyte, and reduces the path distance of ion diffusion. The smaller nanostructures can provide more chemically active sites, thus showing better electrochromic properties.
The work aims to study electrochromic properties of tungsten oxide dihydrate films with different microstructures. Tungsten oxide dihydrate films were prepared on FTO by chemical solution deposition method. Different nanostructured WO_3·2H_2O films were synthesized by adding different morphology control agents(citric acid or ammonium oxalate). The composition and microstructure of the films were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM).UV-visible spectrophotometer was used to study the transmittance of films with wave length within 200～1000 nm and electrochromic performance of the films was investigated by an electrochemical workstation. The transmittance of WO_3·2H_2O film prepared with citric acid as the morphology control agent reached 82%, and the transmittance difference of film in colored and faded state was 36.2%. The WO_3·2H_2O films prepared by adding citric acid or ammonium oxalate as the morphology control agent exhibited nano-sheet structure. The thickness of the nanosheets was 5～15 nm and 50～60 nm, respectively. However,WO_3·2H_2O prepared with citric acid had more gaps and cracks, which exhibited better electrochromic properties. WO_3·2H_2O film with gaps and cracks increases the contact area between the film and the electrolyte, and reduces the path distance of ion diffusion. The smaller nanostructures can provide more chemically active sites, thus showing better electrochromic properties.
引文
[1]尹荔松,周歧发,危韧勇.纳米TiO2薄膜的制备及其光学特性研究[J].中山大学学报(自然科学版),2000,39(4):52-56.YIN Li-song,ZHOU Qi-fa,WEI Ren-yong.Preparation and optical characteristics of nanocrystalline TiO2 thin film[J].Journal of Sun Yat-Sen University,2000,39(4):52-56.
[2]鲁圣国,麦炽良,黄健洪,等.PZT/SiO2透明纳米复合材料的低温荧光特征[J].哈尔滨理工大学学报,2002(6):16-17.LU Sheng-guo,MAI Zhi-liang,HUANG Jian-hong,et al.Low temperature photoluminscence characteristics of PZT/SiO2 transparent nancomposites[J].Journal of Harbin University of Science and Technology,2002(6):16-17.
[3]赵跃智,周思凯,张俊.ZnO薄膜的制备及其性能[J].化工进展,2008,27(8):1277-1279.ZHAO Yue-zhi,ZHOU Si-kai,ZHANG Jun.Preparation and characteristic of ZnO thin films[J].Chemical industry and engineering progress,2008,27(8):1277-1279.
[4]JIAO Z H,WANG X,WANG J M,et al.Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance[J].Chemical communications,2011,48(3):365-367.
[5]GAO T,JELLE B P.Electrochromism of hexagonal sodium tungsten bronze nanorods[J].Solar energy materials&solar cells,2018,177:3-8.
[6]周超,周晖,张凯锋,等.电致变色器件中WO3薄膜高温环境性能退化机理[J].表面技术,2018,47(5):47-52.ZHOU Chao,ZHOU Hui,ZHANG Kai-feng,et al.Degradation mechanism of WO3 film in electrochromic device in high temperature environment[J].Surface technology,2018,47(5):47-52.
[7]DEB S K.A novel electrophotographic system[J].Applied optics,1969,8(101):192-195.
[8]DEB S K.Optical and photoelectric properties and colour centres in thin films of tungsten oxide[J].Philosophical magazine series,1973,27(4):801-822.
[9]CRANDALL R S,FAUGHNAN B W.Dynamics of coloration of amorphous electrochromic films of WO3 at low voltages[J].Applied physics letters,1976,28(2):95-97.
[10]KAWASAKI H,NAMBA J,IWATSUJI K,et al.NOx gas sensing properties of tungsten oxide thin films synthesized by pulsed laser deposition method[J].Applied surface science,2002,197-198:547-551.
[11]CHENG W,BAUDRIN E,DUNN B,et al.Synthesis and electrochromic properties of mesoporous tungsten oxide[J].Journal of materials chemistry,2001,11(1):92-97.
[12]WANG J M,LEE P S,JAN M.One-pot synthesis of hierarchically assembled tungsten oxide(hydrates)nano/microstructures by a crystal-seed-assisted hydrothermal process[J].Crystal growth&design,2009,9(5):2293-2299.
[13]MATHURI S,MARGONI M M,RAMAMURTHI K,et al.Hydrothermal assisted growth of vertically aligned platelet like structures of WO3 films on transparent conducting FTO substrate for electrochromic performance[J].Applied surface science,2018,449:77-91.
[14]AMANO F,LI D,OHTANI B.Fabrication and photoelectrochemical property of tungsten(VI)oxide films with a flake-wall structure[J].Chemical communications,2010,46(16):2769.
[15]JOHANSSON M B,MATTSSON A,LINDQUIST S E,et al.The importance of oxygen vacancies in nanocrystalline WO3-x thin films prepared by DC magnetron sputtering for achieving high photoelectrochemical efficiency[J].Journal of physical chemistry C,2017,121(13):7412-7420.
[16]高玲,尚福亮,杨海涛,等.溶胶-凝胶-热解法制备介孔WO3薄膜及其电致变色性能研究[J].功能材料,2007,38(1):75-77.GAO Ling,SHANG Fu-liang,YANG Hai-tao,et al.Study on the preparation and electrochromic performance of the mesoporous WO3 film by the sol-gel-pyrolysis method[J].Journal of functional materials,2007,38(1):75-77.
[17]代富平,吕淑媛,冯博学,等.非晶态WO3薄膜电致变色特性的研究[J].物理学报,2003,52(4):1003-1008.DAI Fu-ping,LYU Shu-yuan,FENG Bo-xue,et al.Study on electrochromic properties of amorphous WO3 films[J].Acta physicasinice,2003,52(4):1003-1008.
[18]JIAO Zhi-hui,SUN Xiao-wei,WANG Jin-min,et al.Hydrothermally grown nanostructured WO3 films and their electrochromic characteristics[J].Journal of physics Dapplied physics,2010,43(28):285501.
[19]LIVAGE J,GUZMAN G.Aqueous precursors for electrochromic tungsten oxide hydrates[J].Solid state ionics,1996,84(96):205-211.
[20]PATIL S V,MANE R M,PAWAR N B,et al.Opto-structural and electrical properties of chemically grown Ga doped MoBi2Se5 thin films[J].Journal of materials science materials in electronics,2013,24(12):4669-4676.
[21]PATIL P S,MUJAWAR S H,SADALE S B,et al.Effect of film thickness on electrochromic activity of spray deposited iridium oxide thin films[J].Materials chemistry&physics,2006,99(2-3):309-313.
[2]鲁圣国,麦炽良,黄健洪,等.PZT/SiO2透明纳米复合材料的低温荧光特征[J].哈尔滨理工大学学报,2002(6):16-17.LU Sheng-guo,MAI Zhi-liang,HUANG Jian-hong,et al.Low temperature photoluminscence characteristics of PZT/SiO2 transparent nancomposites[J].Journal of Harbin University of Science and Technology,2002(6):16-17.
[3]赵跃智,周思凯,张俊.ZnO薄膜的制备及其性能[J].化工进展,2008,27(8):1277-1279.ZHAO Yue-zhi,ZHOU Si-kai,ZHANG Jun.Preparation and characteristic of ZnO thin films[J].Chemical industry and engineering progress,2008,27(8):1277-1279.
[4]JIAO Z H,WANG X,WANG J M,et al.Efficient synthesis of plate-like crystalline hydrated tungsten trioxide thin films with highly improved electrochromic performance[J].Chemical communications,2011,48(3):365-367.
[5]GAO T,JELLE B P.Electrochromism of hexagonal sodium tungsten bronze nanorods[J].Solar energy materials&solar cells,2018,177:3-8.
[6]周超,周晖,张凯锋,等.电致变色器件中WO3薄膜高温环境性能退化机理[J].表面技术,2018,47(5):47-52.ZHOU Chao,ZHOU Hui,ZHANG Kai-feng,et al.Degradation mechanism of WO3 film in electrochromic device in high temperature environment[J].Surface technology,2018,47(5):47-52.
[7]DEB S K.A novel electrophotographic system[J].Applied optics,1969,8(101):192-195.
[8]DEB S K.Optical and photoelectric properties and colour centres in thin films of tungsten oxide[J].Philosophical magazine series,1973,27(4):801-822.
[9]CRANDALL R S,FAUGHNAN B W.Dynamics of coloration of amorphous electrochromic films of WO3 at low voltages[J].Applied physics letters,1976,28(2):95-97.
[10]KAWASAKI H,NAMBA J,IWATSUJI K,et al.NOx gas sensing properties of tungsten oxide thin films synthesized by pulsed laser deposition method[J].Applied surface science,2002,197-198:547-551.
[11]CHENG W,BAUDRIN E,DUNN B,et al.Synthesis and electrochromic properties of mesoporous tungsten oxide[J].Journal of materials chemistry,2001,11(1):92-97.
[12]WANG J M,LEE P S,JAN M.One-pot synthesis of hierarchically assembled tungsten oxide(hydrates)nano/microstructures by a crystal-seed-assisted hydrothermal process[J].Crystal growth&design,2009,9(5):2293-2299.
[13]MATHURI S,MARGONI M M,RAMAMURTHI K,et al.Hydrothermal assisted growth of vertically aligned platelet like structures of WO3 films on transparent conducting FTO substrate for electrochromic performance[J].Applied surface science,2018,449:77-91.
[14]AMANO F,LI D,OHTANI B.Fabrication and photoelectrochemical property of tungsten(VI)oxide films with a flake-wall structure[J].Chemical communications,2010,46(16):2769.
[15]JOHANSSON M B,MATTSSON A,LINDQUIST S E,et al.The importance of oxygen vacancies in nanocrystalline WO3-x thin films prepared by DC magnetron sputtering for achieving high photoelectrochemical efficiency[J].Journal of physical chemistry C,2017,121(13):7412-7420.
[16]高玲,尚福亮,杨海涛,等.溶胶-凝胶-热解法制备介孔WO3薄膜及其电致变色性能研究[J].功能材料,2007,38(1):75-77.GAO Ling,SHANG Fu-liang,YANG Hai-tao,et al.Study on the preparation and electrochromic performance of the mesoporous WO3 film by the sol-gel-pyrolysis method[J].Journal of functional materials,2007,38(1):75-77.
[17]代富平,吕淑媛,冯博学,等.非晶态WO3薄膜电致变色特性的研究[J].物理学报,2003,52(4):1003-1008.DAI Fu-ping,LYU Shu-yuan,FENG Bo-xue,et al.Study on electrochromic properties of amorphous WO3 films[J].Acta physicasinice,2003,52(4):1003-1008.
[18]JIAO Zhi-hui,SUN Xiao-wei,WANG Jin-min,et al.Hydrothermally grown nanostructured WO3 films and their electrochromic characteristics[J].Journal of physics Dapplied physics,2010,43(28):285501.
[19]LIVAGE J,GUZMAN G.Aqueous precursors for electrochromic tungsten oxide hydrates[J].Solid state ionics,1996,84(96):205-211.
[20]PATIL S V,MANE R M,PAWAR N B,et al.Opto-structural and electrical properties of chemically grown Ga doped MoBi2Se5 thin films[J].Journal of materials science materials in electronics,2013,24(12):4669-4676.
[21]PATIL P S,MUJAWAR S H,SADALE S B,et al.Effect of film thickness on electrochromic activity of spray deposited iridium oxide thin films[J].Materials chemistry&physics,2006,99(2-3):309-313.