以氧化鋅/硫化鋅核殼奈米柱陣列作為具有優越的光降解及光偵測特性之研究

本研究主要是利用簡易的晶種輔助水熱法來製備氧化鋅奈米柱陣列，並且探討不同退火溫度對於氧化鋅奈米柱的直徑、長度、晶體結構及氧空缺的影響，最後以光觸媒及光偵測特性來做為應用上的分析，發現其在晶種退火300℃所成長出的氧化鋅奈米柱具有最好的光觸媒效果，並且在光偵測上有0.8 mA的光增幅效果。　　因為氧化鋅能隙的限制依舊無法突破，目前只能針對紫外光上的應用，文獻上利用許多不同金屬以及昂貴的機台去修飾氧化鋅的表面使其增加可見光的吸收，將花費較多的成本與資源。我們利用簡易的水熱法進行硫化反應並達到表面鈍化的效果，也使得原本容易吸附空氣中的水氣或氫氧基而親水的氧化鋅變成疏水表面，接觸角由原本33o 變為128o，並且改善了氧化鋅的氧缺陷且利用他們的異質介面間接的促進在可見光波長下的吸收，並且能夠有效的分離電子–電洞對，使光觸媒特性更為顯著。　　最後我們再將氧化鋅卅硫化鋅核殼結構摻入銅離子降低電阻提高電流值同時減少氧化鋅內部的氧空缺，並且形成三階的核殼型態，使能隙再降低且更有效的分離電子–電洞對減少再複合的機會，提高光增幅效果，且在光觸媒結果中由於減少電子–電洞對在復合的機會，更能有效的與水反應產生氫氧自由基與超氧離子，達到更有效的光降解特性。

關鍵字

氧化鋅；氧化鋅/硫化鋅；銅摻雜；核殼結構；光偵測；光降解

並列摘要

In this study, a simple seed-assisted hydrothermal method is used to prepare ZnO nanorods array and we investigated the different annealing temperatures on the diameter, length, oxygen vacancy and crystal structure of grown zinc oxide nanorods. We further explored their photocatalytic and photodetection properties as analytical applications. We found that the formed zinc oxide nanorods demonstrated the best photocatalytic effect when the annealing temperature is 3000C, and achieved the largest photocurrent increment (1.8 mA) from photometric measurements. The energy gap of zinc oxide is at UV region, which limits their application of photodetection applications. In the literatures, the use of different metals on the fabrication of ZnO-based photodetectors can modify the surfaces of zinc oxide and further increase the visible-light absorption of zinc oxide, but the process is expensive and complicated. Therefore, a simple hydrothermal method is utilized to form ZnO nanorods with well surface passivation. The surfaces of ZnO nanorods can adsorb water vapor or OH- in the air, and changes from hydrophilic property to hydrophobic characteristic, with a contact angle from 33o to 128o. In addition, it improves the oxygen deficiency of zinc oxide and the heterogeneous surfaces indirectly promote absorption at the wavelength of visible light. It can also effectively separate the electron - hole pairs, resulting in the significant photocatalytic characteristic. Finally, the copper ions were doped in ZnO / ZnS core-shell structure to reduce the electric resistance and oxygen vacancies in the interior of zinc oxide. The formation of three-elvel core-shell patterns, makes the reduction of energy gap and the efficient separation of the electron/hole pairs, leading to the increased photocurrent. The photocatalyst results, due to reduced opportunities of electron - hole pair recombination, which more effectively react with water to produce hydroxyl radicals and superoxide ions, achieving a more efficient light degradation characteristics.

並列關鍵字

ZnO ； ZnO/ZnS ； Cu doped ； Core-shell ； Photodetector ； photocatalyst

參考文獻

[1] Zafar Hussain Ibupoto, Hydrothermal Growth of Vertically Aligned ZnO Nanorods Using a Biocomposite Seed Layer of ZnO Nanoparticles, Materials 2013, 6, 3584-3597

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[2] Chong-Xin Shan, Enhanced Responsivity of Photodetectors Realized via Impact Ionization, Sensors 2012, 12, 1280-1287

Google Scholar

[3] Tse-Pu Chen, Bending effects of ZnO nanorod metal–semiconductor–metal photodetectors on flexible polyimide substrate, Nanoscale Research Letters 2012, 7, 1-6

Google Scholar

[4] Meng Sun, Fabrication and Wettability of ZnO Nanorod Array, J. Mater. Sci. Technol., 2009, 25, 53-57

Google Scholar

[5] Jiangni Yun, Magnetic Properties of Well-Aligned ZnO Nanorod Arrays, Condensed Matter Physics, 2014, 2014, 1-6

Google Scholar

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以氧化鋅/硫化鋅核殼奈米柱陣列作為具有優越的光降解及光偵測特性之研究

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