銅微柱之電化學製作與其表面奈米氧化鋅被覆研究

Electrochemical Fabrication of Copper Microcolumns and their Coating of Nano ZnO

本研究之目的在探討電化學被覆奈米氧化鋅於金屬銅微柱表面的可行性。首先以即時影像微陽極導引連續電鍍法自硫酸銅溶鍍液中，製作出直徑為80μm之單軸銅微柱，接著企圖在其表面進行奈米氧化鋅的電化學被覆。藉由三極式電鍍法中的精密控制電位、鍍浴濃度、電鍍時間等參數之改變，觀察這些參數對所被覆奈米氧化鋅形貌之影響。由場發射掃描式電子顯微鏡觀察得知：金屬銅微柱於含20 mM過氧化氫的2 mM硫酸鋅水溶液中，控制電位在-0.96 V （vs. Ag/AgCl）下電鍍20分鐘，可以在微柱表面獲得氧化鋅奈米柱之被覆。奈米氧化鋅被覆層，經光致發光光譜（photoluminescence）分析顯示：光源為330 nm之激發光，在387 nm及396 nm波長處產生較強烈之放射光譜（emission）峰值。改變電鍍參數，可以調整氧化鋅奈米柱之層狀排列，提升其比表面積，未來在氣體偵測的應用具有發展潛力。

Coating feasibility of nano-ZnO on a copper micro-column was of interest in this work. The copper micro-columns, in an average diameter of 80 μm, were prepared from a bath of copper sulfate by a novel method of real-time image-monitoring micro-anode guided continuous electroplating. The electrochemical coating of nano- ZnO was carried out with a three-electrode electroplating system. Surface morphology of the nano-coating influenced by the experimental parameters such as deposition potential, bath composition and deposition time was investigated. Examination through field emission scanning electron microscope, we found that electrochemical coating of nano-ZnO was feasible from a bath containing 2 mM zinc sulfate and 20 mM hydrogen peroxide at a potential of -0.96 V (vs. Ag/AgCl ) for 20 minutes. Analysis of photoluminescence spectroscopy of the nano-ZnO coating indicated that an excitation with 330 nm leading to two intense emission peaks at 387 nm and 396 nm. Under adequate control of electrochemical condition, the nano-ZnO coating revealed a layer structure accumulated by ZnO nanorods which indicated a huge specific area to be considered as a potential candidate for gas-sensing materials.