無電鍍沉積的反應中，需要透過觸媒降低金屬離子還原反應的活化能。鈀金屬觸媒因具有優異的催化活性而廣為工業界應用，但隨著鈀金價格日益高漲，鈀合金或無鈀觸媒的技術開發變得越來越重要。銀金屬觸媒是文獻中較常見的無鈀觸媒選擇之一，但尚未實現真正工業化。本研究合成奈米級鈀觸媒與銀觸媒，並比較兩者在無電鍍銅及無電鍍銀沉積中的表現，同時討論其催化活性及反應機制。最後試著將這兩種奈米金屬觸媒用於石墨粉表面銀金屬化，評估其在矽晶太陽能電池產業中降低銀漿成本的應用可行性。具體來說，本研究分為兩個部分。
第一部分是透過高分子聚乙烯醇(PVA)作為分散劑來合成奈米鈀觸媒(PVA-Pd)及奈米銀觸媒(PVA-Ag)，透過紫外光可見光光譜儀(UV-Vis)及穿透式電子顯微鏡(TEM)確認觸媒的金屬價態及粒徑後，將兩種觸媒用於催化無電鍍銅及銀沉積，兩種金屬的無電鍍沉積皆使用甲醛作為還原劑。由比活性之分析結果可知，PVA-Pd在無電鍍銅沉積上之活性明顯優於PVA-Ag，這是由於鈀金屬能幫助氫原子在其表面快速且完整的氧化釋出電子，但PVA-Ag仍能透過增加觸媒於欲鍍材料表面的吸附量來達到相近的無電鍍銅沉積表現。而無電鍍銀沉積的部分結果卻呈現反轉的現象，意即PVA-Pd之比活性相較於銅沉積出現明顯下滑，但PVA-Ag之比活性卻反而有些微上升，根據金屬觸媒是以幫助還原劑氧化來催化金屬離子沉積之理論前提，在還原劑相同的情況下，顯然PVA-Ag於無電鍍銀沉積的反應中，可透過幫助氫原子氧化以外之其他機制來催化同種金屬沉積的發生。
第二部分是將PVA-Ag與PVA-Pd應用於石墨粉上進行無電鍍銀沉積，首先透過Hummers method將石墨表面氧化，使表面產生含氧之官能基，接著以胺基矽烷化合物進行表面改質以吸附金屬觸媒，但目前結果顯示由於觸媒吸附量未達可沉積銀層之標準，僅銅可沉積於石墨粉表面。現今在矽晶太陽能產業中，銀漿價格是降低矽晶太陽能電池成本的關鍵之一，因此於石墨表面沉積銀層在此領域中具應用潛力，若能使用外層沉積銀層的石墨來取代銀漿，便可減少純銀的使用量來達到降低成本的目標。

In electroless deposition reactions, we need to reduce the activation energy of the metal ions reduction reaction by using catalysts. Palladium metal catalysts are widely used in industry because of their excellent catalytic activity. However, with the increasing price of palladium, the development of palladium alloys or palladium-free catalysts is becoming increasingly important. Silver catalysts are one of the common choices of palladium-free catalysts in recent researches but have not yet been truly industrialized. This study synthesized nano-palladium and nano-silver catalysts and compared their performance in electroless copper and silver deposition. Their catalytic activity and reaction mechanism were also discussed. Finally, these two nano-metallic catalysts were used for silver-metalization on graphite powder surfaces to evaluate their applicability in the silicon solar cell industry to reduce the cost of silver paste. Specifically, this study is divided into two parts.
In the first part, nano-palladium catalyst (PVA-Pd) and nano-silver catalyst (PVA-Ag) were synthesized by using polymer polyvinyl alcohol (PVA) as a dispersant. Two catalysts are used to catalyze the electroless deposition of copper and silver, and formaldehyde is used as a reducing agent for the electroless deposition of both metals. From the specific activity analysis results, it is clear that PVA-Pd is more active than PVA-Ag in the electroless copper deposition because the palladium metal can help the hydrogen atoms to oxidize wholly and quickly on its surface to release electrons. However, PVA-Ag can still achieve similar electroless copper deposition performance by increasing the adsorption amount of the catalyst on the target material. Moreover, the specific activity results of electroless silver deposition are reversed, the specific activity of PVA-Pd decreases significantly compared with its performance in copper deposition, but the specific activity of PVA-Ag increases slightly. It shows that metal catalysts can catalyze the deposition of the same metal by a mechanism other than assisting the oxidation of hydrogen atoms.
The second part is the application of PVA-Ag and PVA-Pd to electroless silver deposition on graphite powder. The graphite surface was first oxidized by Hummers' method to produce oxygen-containing functional groups, then modified with amine-based silane compounds to adsorb catalysts. However, the current results showed that only copper could be deposited on the graphite powder surface because the adsorption amount of catalysts did not reach the standard for silver deposition. In the silicon solar industry, the price of silver paste is one of the keys to reduce the cost of silicon solar cells. Therefore, the graphite powders covered with silver layer may have the potential to substitute for silver paste, thus reducing the amount of pure silver used.

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