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Title: | 於檸檬酸浴中電鍍鎳磷合金及其電催化性質研究 Electrodeposition and Electrocatalytic Properties of Nickel-Phosphorus Alloys from Citric Baths |
Authors: | Shih-Tsung Wang 王世宗 |
Advisor: | 林招松(Chao-Sung Lin) |
Keyword: | 檸檬酸浴,鎳磷合金,電催化活性,吸附氫能力, nickel citric bath,Ni-P alloy coating,electrocatalytic activity,hydrogen adsorption capability, |
Publication Year : | 2006 |
Degree: | 碩士 |
Abstract: | 本研究於檸檬酸浴中,藉由不同電鍍製程參數來製備鎳磷合金鍍層,並探討製程參數與電解液溫度對鎳磷合金鍍層在酸性電解液中電催化活性之影響。
研究結果顯示電鍍製程參數與鍍層電催化活性有一定關係存在,隨著電流密度、次磷酸鈉濃度與鍍層厚度增加,以及改變檸檬酸濃度能有效提高鍍層電催化活性能力。由I-t曲線發現鍍層吸附氫能力正比於電催化活性能力,但是有一飽和值存在。此外,鍍層磷含量雖不受電流密度影響,但電催化活性能力隨電流密度提高而增加,且經XRD與TEM分析後,顯示鍍層結構皆為非晶態組織,不受電鍍製程參數影響。然而隨著電解液溫度增加會降低鍍層電催化活性能力,顯示電解液溫度升高不利於鍍層電催化活性反應發生,推測為溫度增加促進鍍層表面上有氧化膜生成,導致鍍層電催化活性能力降低。鍍層經十小時陰極極化後,發現鍍層抗蝕性優良且不影響其電催化活性能力,顯示於檸檬酸浴下所製備之鎳磷合金鍍層為一良好的電極材料。 Various Ni-P alloy coatings were electroplated from nickel citric baths, with emphasis on the composition of the solution and the electroplating current density. Hydrogen evolution reaction of the deposits in acid electrolytes at different temperatures was systemically studied. Experimental results show that the electrocatalytic activity of the deposit can be correlated to the composition of the solution and the electroplating current density. Ni-P deposits with improved electrocatalytic activity were made by increasing the current density, electroplating time, and solution sodium hypophosphite concentration, while immediate amounts of citric anions were added to the solution. Moreover, the deposit that absorbed more hydrogen during cathodic polarization exhibited better electrocatalytic activity, as shown in the I-t curves. Nevertheless, a saturated electrocatalytic activity was observed for the deposit with an ever-increasing hydrogen adsorption capability. The deposit phosphorus content hardly changed with the electroplating current density, whereas the electrocatalytic activity of the deposit increased with increasing electroplating current density. All deposits studied were amorphous as characterized by XRD and TEM. The electrocatalytic activity of the deposit became poor when measured in the electrolytes at higher temperatures. This is likely to be due to the formation of a surface oxide film in the high-temperature electrolyte. Finally, the electrocatalytic activity of the deposit displayed insignificant change after 10 h of cathodic polarization. This indicates that the Ni-P deposits plated from nickel citric baths had excellent corrosion resistance in acid solutions, signifying they can be the electrode for hydrogen evolution in acid electrolytes. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/32987 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 材料科學與工程學系 |
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ntu-95-1.pdf Restricted Access | 4.19 MB | Adobe PDF |
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