釕氧化物、鎳氧化物與 Nafion及多層奈米碳管複合薄膜修飾電極的電化學製備及其電催化性質之研究

Characterization of ruthenium oxide、nickel oxide with Nafion and multiwall carbon nanotubes hybrid modified electrodes and its enhancements in electrocatalytic reactions.

邸建傑(Chien-Chieh Ti)

指導教授 ： 陳生明

國立臺北科技大學/工程學院/化學工程研究所/碩士(2006年)

摘要

本研究主要分為三部分來討論，第一部份利用利用玻璃碳電極(GCE) 在pH=2緩衝溶液中修飾氧化釕(RuOx)/Nafion (Nf) 薄膜，實驗中使用了循環伏安法(CV)、電化學石英晶體微天平(EQCM)、旋轉環碟電極法(RRDE) 及掃描式電子顯微鏡(SEM) 探討其電化學性質及特性。本研究主要是使用循環伏安法使氧化釕穩定沉積在Nafion修飾電極上，形成氧化釕/Nafion(Nf) 薄膜修飾電極，利用電化學石英晶體微天平(EQCM) 觀察其在電極上的成長情形，旋轉環碟電極法(RRDE) 則是用來研究其電催化反應，並用掃描式電子顯微鏡(SEM) 觀察氧化釕結合在Nafion聚合薄膜上的表面現象。在電催化反應，氧化釕/Nafion薄膜對多巴胺(DA) 與抗壞血酸(AA)有良好的電催化氧化活性，DA與AA的氧化波峰電位分別是609與316 mV，而在RuO/Nf修飾電極上可看出DA的催化作用大於AA及尿酸(UA)。在pH=2溶液中，陽極波峰電流會隨著DA的濃度上升而呈線性增加 (5.0×10−7 – 1.0×10−6 M 間)，相關係數為0.994而偵測極限為5.0×10−8 mol l−1。在電催化效果中，同時加入DA及AA會產生2個分開的陽極波峰，正負波峰間電位差約為290 mV。這可以用來說明DA的催化效果會大於AA及UA。此修飾電極也展現出良好的選擇性、穩定性及防污的特效。
第二部分的氧化釕-奈米碳管薄膜(MWCNTs-RuOx) 是一種新的傳導性複合薄膜，包含多層奈米碳管(MWCNT) 與釕氧化物(RuOx)，可藉由電位靜力學法製備在玻璃碳電極(GCE) 、黃金電極(Au) 、銦錫氧化物電極(ITO) 和網板碳電極(SPCE) 上。多層奈米碳管的存在增大了釕氧化物的表面覆蓋濃度(Γ)。此複合薄膜在pH=3水溶液下對生物化學化合物，如腎上腺素(EP) 、正腎上腺素(NEP) ，有高度的電催化氧化效應。我們使用循環伏安法和流動式注射分析法對在複合薄膜修飾電極上的神經傳導物質做電化學分析。經由多層奈米碳管修飾後的釕氧化物薄膜在靈敏度上高於其他常用的修飾電極。而且此複合薄膜在電化學石英晶體微天平的黃金電極上藉由多層奈米碳管展現出更多的釕氧化物沉積量。我們也使用了掃描式電子顯微鏡觀察複合薄膜沉積在透明的銦錫氧化物電導體的表面型態，可看出釕氧化物與奈米碳管明顯的結合。
第三部分的鎳氧化物-奈米碳管薄膜(MWCNTs-NiOx) 也是一種新的傳導性複合薄膜，包含多層奈米碳管(MWCNT) 與鎳氧化物(NiOx) ，可藉由電位靜力學法製備在玻璃碳電極(GCE) 、黃金電極(Au) 和銦錫氧化物電極(ITO) 上。多層奈米碳管的存在增大了鎳化物的表面覆蓋濃度(Γ)。此複合薄膜在pH13水溶液下對H2O, H2O2, N2H4, NH2OH, aspirin和succinic acid等，有高度的電催化氧化效應，我們使用循環伏安法對在複合薄膜修飾電極上的上述複合物做電化學分析。經由多層奈米碳管修飾後的鎳氧化物薄膜在靈敏度上高於其他常用的修飾電極。而且此複合薄膜在電化學石英晶體微天平的黃金電極上藉由多層奈米碳管展現出更多的鎳氧化物沉積量。我們也使用了掃描式電子顯微鏡觀察複合薄膜沉積在透明的銦錫氧化物電導體的表面型態，可看出鎳氧化物與奈米碳管明顯的結合。

關鍵字

釕氧化物 ； 鎳氧化物 ； Nafion ； 多巴胺 ； 奈米碳管 ； 腎上腺素 ； 正腎上腺素 ； H2O2 ； N2H4 ； NH2OH ； aspirin ； succinic acid ； 電催化 ； 薄膜修飾電極

並列摘要

Part Ⅰ：A glassy carbon electrode (GCE) is modified with ruthenium oxide/nafion film (RuO/Nf/GCE) in pH 2.0 buffer solution. Cyclic voltammetry (CV), electrochemical quartz crystal microbalance (EQCM), rotatable ring disk electrode (RRDE) and amperometric techniques were used to study the electrochemical properties of the RuO/Nf film. Scanning electron microscope (SEM) and atomic force microscope (AFM) revealed that ruthenium oxide particles incorporated onto the nafion polymer film. RuO/Nf/GCE film modified electrode showed excellent electrocatalytic activity for the oxidation of dopamine (DA) and ascorbic acid (AA). The DA and AA anodic peak potential values at the modified electrode are 609 and 318mV, respectively. The RuO/Nf/GCE film-modified electrode is used to electrochemically detect DA in the presence of AA and uric acid (UA). In pH 2.0 acidic solution, the anodic peak current increases linearly over the concentration of DA 5.0×10−7 – 1.0×10−6, with the correlation coefficient of 0.994, and the detection limit (S/N = 3) is 5.0×10−8 mol l−1. Owing to the catalytic effect of the modified film towards dopamine, the modified electrode resolved the overlapped voltammetric responses of ascorbic acid and dopamine into two well-defined voltammetric peaks with peak-to-peak separation in potentials of about 290 mV. This can be used to allow the determination of dopamine in the presence of ascorbic acid and uric acid. The modified electrode showed good selectivity, stability and anti-fouling properties.
Part II：A novel conductive composite film (MWCNTs-RuOx) containing multi-walled carbon nanotubes (MWCNT) with ruthenium oxide (RuOx) was synthesized on glassy carbon electrode (GCE), gold (Au) and indium tin oxide (ITO), screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of MWCNTs in the composite film enhanced the surface coverage concentration (Γ) of RuOx. The composite film exhibited a promising higher catalytic activity towards the oxidation of biochemical compounds such as epinephrine (EP) and epinephrine (NEP) in pH 3.0 aqueous solution. Both the cyclic voltammetry (CV) and flow injection analysis (FIA) were used for the measurement of electroanalytical properties of neurotransmitters by means of composite film modified electrodes. The MWCNTs-RuOx modified GCE sensitivity values were higher than the values obtained for other film modified GCEs. Further the composite films produced on Au electrode were used for electrochemical quartz crystal microbalance studies, which revealed the enhancements in the functional properties of MWCNTs and RuOx. The surface morphology of the composite films deposited on transparent semiconductor ITO were studied using scanning electron microscopy, which revealed that RuOx incorporated on MWCNTs
Part III：A novel conductive composite film (MWCNTs-NiOx) containing multi-walled carbon nanotubes (MWCNT) with nickel oxide (NiOx) was synthesized on glassy carbon electrode (GCE), gold (Au) and indium tin oxide (ITO) by potentiostatic methods. The presence of MWCNTs in the composite film enhanced the surface coverage concentration (Γ) of NiOx. The composite film exhibited a promising higher catalytic activity towards the oxidation of compounds such as H2O, H2O2, N2H2, NH2OH, aspirin and succinic acid in aqueous solutions. The cyclic voltammetry (CV) were used for the measurement of electroanalytical properties of the analytes by means of composite film modified electrodes. Further the composite films produced on Au electrode were used for electrochemical quartz crystal microbalance studies, which revealed the enhancements in the functional properties of MWCNTs and NiOx. The surface morphology of the composite films deposited on transparent semiconductor ITO were studied using scanning electron microscopy, which revealed that NiOx incorporated on MWCNTs.

並列關鍵字

Ruthenium oxide ； Nickel oxide ； Nafion ； dopamine ； Multiwall carbon nanotubes ； Epinephrine ； Norepinephrine ； Neurotransmitters ； H2O2 ； N2H2 ； NH2OH ； Aspirin ； Succinic acid ； Electrocatalysis ； Film modified electrodes

參考文獻

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