製備鉑/靜電紡絲碳纖維奈米複合電極應用於電催化水相結晶紫之降解

Assembly of Pt nanoparticles on electrospun carbon fibers for electrocatalytic degradation of crystal violet

黃鈺玲(Yu-Ling Huang)

指導教授 ： 林正芳

共同指導教授 ： 侯嘉洪(Chia-Hung Hou)

國立臺灣大學/工學院/環境工程學研究所/碩士(2020年)

https://doi.org/10.6342/NTU202003677

摘要

隨著全球氣候變遷、人口量上升及工業發展日益顯著，面對嚴峻的水能源危機，廢污水相關新興水處理技術的開發愈發重要。其中，電催化作為一新興電化學水處理技術，由於其高去除效率、高能效、環境相容性高且化學藥品添加量少之優勢，備受現今研究圈關注。在眾多電催化劑中，鉑 (Platinum，Pt) 具備優秀的化學抗性和電催化效率，惟價格較高。因此本篇研究選用鉑作為電催化劑，並與靜電紡絲碳纖維複合製備奈米複合式之三維Pt/CF電極，降低Pt負載量同時保有優良的電催化活性。在材料製程中，透過鉑前驅溶液的還原時間有效控制Pt顆粒之粒徑與分佈，確保Pt催化劑得到最佳利用。根據本研究結果可推論，Pt /CF電極的電催化性能高度取決於Pt催化劑之粒徑大小。於兩小時還原時間下製備之Pt/CF-r2hr電極由於具備最小的平均粒徑 (24.17 nm) 且Pt顆粒均勻分佈，因此展現出良好的電化學活性面積 (18.98 m2 g-1-Pt) ，並在1 V的低電壓操作及低能耗 (0.26 kW m-3 order-1) 條件下，達到94.96％的結晶紫去除效率。機制探討部分，在添加新丁醇 (tert-Butanol, BuOH) 做為羥基自由基清除劑後發現，Pt/CF電極在沒有羥基自由基的參與仍可降解60％以上的結晶紫，因此推斷Pt/CF電極的電催化降解機制可能同時涵蓋直接氧化及間接氧化兩種途徑。
由本研究結果可知，Pt/CF作為一個具發展潛力的奈米複合式電催化電極，可在低能量輸入下有效降解環境有機污染物。同時奈米催化劑顆粒之粒徑分布，為貴重金屬催化電極之關鍵特性條件，有效控制催化劑顆粒將可使材料之電催化效能達到顯著提升。

關鍵字

鉑 ； 靜電紡絲 ； 電催化 ； 粒徑 ； 結晶紫

並列摘要

Owing to the enhancement of climate change, population growth, and industrial evolution, the development of novel treatments to reduce energy associated with wastewater treatment is an urgent issue to reduce the water-energy crisis. Electrocatalysis with engineered nanomaterials is an emerging electrochemical water treatment technology which attracts great attention due to its high removal efficiency, high energy efficiency, environmental compatibility, and few chemicals requirement. In this study, platinum was chosen as the electrocatalyst due to its great demonstration in chemical resistance and electrocatalytic efficiency, compositing electrospun carbon fiber as a binder-free supporter to fabricate three-dimensional Pt/CF electrodes. To ensure the optimum utilization of Pt catalyst, the particle size and distribution of Pt are well controlled by the precursor reduction time during the impregnation process. The present work shows that the electrocatalytic performance of Pt/CF is highly determined by the particle size of Pt catalyst. The Pt/CF electrode, which was reduced for 2 hours during impregnation, behaves the smallest mean particle size with uniform distribution, leading to a good electrochemical catalyst surface activity (18.98 m2 g-1-Pt) and removal efficiency of crystal violet (94.96%) at a low voltage of 1 V with low EEO value (0.26 kW m-3 order-1). By the addition of hydroxyl radical scavenger, it is discovered that more than 60% of crystal violet still could be degraded without the participation of the hydroxyl radical, indicates that the mechanism of electrocatalysis via Pt/CF may have two pathways, including direct and indirect oxidation. The results suggest that Pt/CF is a desirable electrocatalytic electrode for the degradation of organic pollutants with low energy input. Controlling the nanoparticle size could be a key parameter for electrocatalysis of environmental organic pollutants by the noble metal catalytic electrode.

並列關鍵字

platinum ； electrospinning ； electrocatalysis ； particle size ； crystal violet

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