- 學位論文
用於氧氣還原及葡萄糖偵測之海綿狀鈀銅奈米粒子
Palladium Copper Nanosponges for Electrocatalytic Reduction of Oxygen and Glucose Detection
摘要
本研究開發一快速方法來一鍋合成 (one-pot synthesis) 海綿狀鈀銅奈米粒子 (palladium copper nanosponges, PdCu NSs) ，其合成的方法為在95 °C且有十二烷基硫酸鈉 (sodium dodecyl sulfate) 存在下，以抗壞血酸 (L-ascorbic acid) 來還原鈀離子以及銅離子。藉由調控十二烷基硫酸鈉的濃度 (12.5, 25.0和37.5 mM) ，不但能夠合成出大小不同的海綿狀奈米粒子，也能改變此材料對於氧氣的電催化活性。上述條件合成的海綿狀鈀銅奈米粒子與相同方法所合成出的鈀奈米粒子 (電流密度: 0.33 mA cm-2) 、銅奈米粒子 (電流密度: 0.31 mA cm-2) 、市售的鉑/碳材料 (電流密度: 0.66 mA cm-2) 以及市售的鈀/碳材料 (電流密度: 0.34 mA cm-2) 相比較，此種材料可提供較佳的氧氣還原電流密度 (1.93 mA cm-2) 。這是由於其具有極高的電化學活性表面積 (385.5 m2 g-1) 以及鈀銅雙金屬間的協同效應，使得海綿狀鈀銅奈米粒子表現出優異的電催化活性。此外，本最佳化材料對於葡萄糖亦具有優異的電催化效果，經過43,200秒進行計時安培法量測後，其仍具有極佳的穩定度。與現有文獻方法相比，本方法所合成之材料具有高靈敏性 (1560 μA mM-1 cm-2) 、高選擇性、偵測極限較低 (為4.1 μM) 、使用壽命久等優點。此電化學穩定度高、高催化活性且低成本的海綿狀鈀銅合金奈米粒子修飾之碳電極，不僅可運用於甲醇燃料電池，對於作為非酵素型葡萄糖感測器亦具有極佳的潛力。
並列摘要
A facile and one-pot wet chemical approach has been applied for the preparation of palladium copper (PdCu) nanosponges (NSs) through the reduction of Pd2+ and Cu2+ ions with L-ascorbic acid in the presence of sodium dodecyl sulfate (SDS) at 95 °C. The PdCu NSs prepared in the presence of 12.5, 25, and 37.5 mM SDS have different sizes and catalytic activity for oxygen reduction reaction. Relative to a Pd NPs electrode (0.33 mA cm-2), Cu NPs electrode (0.31 mA cm-2), commercial Pd/C electrode (0.34 mA cm-2) and Pt/C electrode (0.66 mA cm-2), PdCu NS-modified electrodes provide high current density for oxygen reduction reaction (1.93 mA cm-2) under alkaline conditions. The higher catalytic activity of the PdCu NSs is mainly due to their greater electroactive surface area (EASA) and synergistic effect caused by the intimate contact between Pd and Cu. In addition, the PdCu NS-modified electrodes provide high catalytic activity for glucose oxidation at 0.01 V vs. Ag/AgCl and are stable even after sweeping for 43200 s in 0.1 M NaOH containing 0.1 M glucose. The PdCu NS-modified electrodes exhibit high sensitivity (1560 μA mM-1 cm-2), good selectivity, and fast response to glucose over a linear range of 0-30 μM (R2 = 0.997), with a limit of detection (LOD) of 4.1 μM. With the advantages of good stability, excellent electrocatalytic activity, and cost effectiveness, PdCu NSs hold great potential for use in fuel cells using methanol or ethanol as fuel and for the fabrication of electrochemical sensor for the detection of glucose in blood samples.