透過您的圖書館登入
IP:44.222.87.38
  • 學位論文

奈米氧化鎢之製備與微結構與光電特性之研究

A study on preparation, micro-structure, optical, and electrical properties of nano Tungsten Oxide

指導教授 : 蘇程裕

摘要


奈米材料(Nanostructured Materials)因其具有特殊的光、電、磁、熱和機械等物理及化學特性,本論文研究主題乃以電漿電弧為加熱源,蒸發鎢靶材,並藉由氣凝合成機制,外加一套吹氣裝置,製備奈米氧化鎢粉末。在不同氧氣的流量下,分別探討其微結構、光學和電性的特性。 研究結果顯示,在充足氧氣環境中的WO3(氬:氧=1:1)及少量氧氣環境中之WO3(氬:氧=1:0.5),兩者顆粒分散性皆較差,且團聚現象嚴重,兩者之UV(Ultraviolet)檢測在470 nm之內均有強烈的吸收現象,超過470 nm以上不吸收,經PL(Photoluminescence)測試物性不發光,且兩者皆為黃色粉末。 WO3(氬:氧=1:1)之FTIR(Fourier Transform Infrared)偵測有兩次吸收度,第一次在波長1100 nm之處有強烈的吸收度,另一次在波長1700nm之處但並無前次強烈,其電位不穩定。而WO3(氬:氧=1:0.5)之FTIR偵測在波長1100 nm之處有強烈的吸收度,從1100~3400 nm吸收度隨波長增加而逐漸減少,電位穩定。 W19O55在有微量的氧氣的環境中,顆粒分散比較好,顆粒大小比較平均,UV檢測在小於460 nm之內有強烈的吸收現象,超過460 nm以上較難吸收,經PL測試物性不發光,FTIR偵測在波長1100 nm有強烈的吸收度,從1100~3400 nm吸收度隨波長增加而逐漸減少,電位穩定,為黃藍色粉末。 W24O68在沒有氧氣的環境中,分散比較差,顆粒有團聚的現象,UV檢測在450 nm被強烈的吸收,超過450 nm被穿透,經PL測試物性不發光,FTIR偵測有兩次吸收度,第一次在波長1000 nm有較強烈的吸收度,另一次在波長2350 nm並無前次強烈,電位穩定,為藍色粉末。

並列摘要


Nanostructural materials have specific physical and chemical properties, such as, optical, electrical, magnetic, and mechanical properties. In this study, nanostructural WO3 powders were prepared by a modified plasma arc gas condensation technique where a gas nozzle was introduced to provide blowing gas. The micro-structural, optical, and electrical properties against different flow of oxygen were discussed respectively. Results show that WO3 (Ar:O2=1:1) and WO3 (Ar:O2=1:0.5) both provide higher concentrated particle size distribution and the cluster phenomenon of them are obvious. Here, WO3 (Ar:O2=1:1) denotes WO3 obtained by the proportion of Ar to O2 which is set to 1:1. They both can effectively absorbs ultraviolet (UV) light below the 470 nm, and have no absorption over than 470 nm. And they present non-luminescence by PL (Photoluminescence) experiment. Their powders present yellow. From the analysis of FTIR spectroscopy, the major absorption of WO3 is at 1100 nm and its minor absorption is at 1700 nm. The analysis of FTIR spectroscopy shows the major absorption of WO3 (Ar:O2=1:0.5) is at 1100 nm and its absorption decreases when the wavelength increases among 1100-3400nm. The zeta potential of WO3 (Ar:O2=1:0.5) is stable. W19O55 obtained under thin oxygen presents dispersive particle size distribution and the variance of its particle size is smaller than that of above. The absorption of W19O55 is strong below 460 nm and becomes poor over 460 nm. The result of PL experiment of W19O55 presents no non-luminescence. The result of FTIR shows that its absorption is strong at 1100 nm, and decreases when its wavelength increases among 1100-3400nm. The zeta potential of W19O55 is stable. Its powders present blue. W24O68 is generated under the conditions, without oxygen. It presents higher concentrated particle size distribution and the cluster reaction was found around these larger particles. Its absorption of UV light is strong at 450 nm and the transmission was occurred over than 450 nm. The result of PL experiment of W24O68 presents no non-luminescence. Its FTIR results show that its major absorption is at 1000 nm and minor absorption is at 2350 nm. Its zeta potential presents stable. Its powders are blue.

參考文獻


[27] 洪伯瑜, “溶膠凝膠法製備二氧化鈦及其光催化性質的分析,” 國立台北科技大學有機高分子研究所碩士論文, 2003.
[14] John S. Beaty, Belmon; Jonathan L. Rolfe, North Easton, “Method and Dapparatus for Manufacturing Ultrafine Particles”,U.S. p.5062936, Nov. 5, 1991.
[1] G. L. Frey, A. Rothschild, J. Sloan, R. Rosentsveig, R. Popovitz-Biro, and R. Tenne, ”Investigations of Nonstoichiometric Tungsten Oxide Nanoparticles,” Journal of Solid State Chemistry, vol. 162, p.p. 300-314, 2001.
[2] A. Hjelm and C. G. Granqvist, ”Electronic Structure and Optical Properties of WO3, LiWO3, NaWO3, and HWO3”, Physical Review B Vol. 54, p.p. 2436-2445, 1996.
[3]X. He, J. Li, X. Gao and L. Wang, ”NO2 Sensing Characteristics of WO3 Thin Film Microgas Sensor”, Sensors and Actuators B93, p.p. 463-467, 2003.

延伸閱讀