以嵌段共聚物製備金屬與氮摻雜碳材及其氧還原活性之探討

Metal-incorporated and nitrogen-doping carbons for oxygen reduction activity fabricated by pyrolysis of block copolymers

盧燕興(Yen-hsing Lu)

指導教授 ： 孫亞賢

國立中央大學/工學院/化學工程與材料工程學系/碩士(2015年)

摘要

以嵌段共聚物奈米結構製備銀與氮摻雜碳材，利用顯微影像 (AFM、FESEM、TEM) 、X光散射分析 (GI-SAXS)、X-ray 光電子能譜儀 (XPS)、交流阻抗分析 (EIS)、循環伏安 (CV) 和旋轉圓盤電極 (RDE)等儀器對材料的形貌、結構、成分、電化學性質進行測量，結果顯示由嵌段共聚物製備銀與氮摻雜碳材(CTNC-Ag-400)，其在飽和氧氣的0.1 M KOH溶液中對氧還原反應(ORR)的電催化性能最佳，在1600 rpm下起峰電位為 -0.1 V(v.s SCE)和電流密度3.9 mA/cm2，電子轉移數為3.8，歸因於奈米銀粒子有還原過氧化物的能力。以兩種四氯金酸水溶液電置換銀與氮摻雜碳材，利用顯微影像 (AFM、FESEM、TEM、HR-TEM) 、X光散射分析 (GI-SAXS)、X-ray 光電子能譜儀 (XPS)、X射線能譜元素分析(EDS) 、循環伏安 (CV) 和旋轉圓盤電極(RDE)等儀器對材料的形貌、結構、成分、電化學性質進行測量，其中以K-gold solution電置換半小時製備金@銀與氮摻雜碳材的氧還原活性最佳，在1600 rpm轉速下起峰電位為-0.1 V (v.s SCE)和電流密度為4.8 mA/cm2，電子轉移數為3.9，歸因於金粒子尺寸小活性大有利於四電子還原。

關鍵字

氮碳參雜碳材 ； 金屬參雜碳材 ； 氧還原活性

並列摘要

Silver-incorporated and nitrogen-enriched nanocarbons with well-defined morphology are synthesized by pyrolysis of self-assembled block copolymer. The morphologies, structures, compostions, and electrocatalytic activities of the as-prepared materials were investigated using atomic force microscope (AFM)、field-emission scanning electron microscope(FESEM)、transmission electron microscopy(TEM) 、grazing-incidence small-angle x-ray scattering (GI-SAXS)、x-ray photoelectron spectroscopy (XPS)、electrochemical impedance spectroscopy (EIS)、cyclic voltammetry (CV) and ratating disk electrode (RDE). The results show that silver-incorporated and nitrogen-enriched nanocarbons with a well-defined morphology were synthesized by pyrolysis of self-assembled block copolymer display good electrocatalytic activity in oxygen reduction reactions (ORR) in O2-saturated alkain solution. At 1600 rpm, it exhibits an ORR onset potential of about -0.1 V (v.s SCE) and the corresponding ORR current density (J) reaches 3.8 mA/cm2. The transferred electron number (n) was 3.8. The reason is that peroxide reduction on silver nanoparticles (Ag NPS) is conducted and Ag NPS enhance the activity of nitrogen-enriched nanocarbons. Here, two types of HAuCl4 solutions are as a second metal precursor involving 0.1 mM HAuCl4 aqueous solution and K-Gold solution. The silver-incorporated and nitrogen-enriched nanocarbons are subject to galvanic replacement reactions (GRRs) in 0.1 mM HAuCl4 aqueous solution and K-gold solution. The GRR of Ag NPs in the K-gold solution yield nonporous Ag/Au nanoparticles (core is sliver and shell is silver/gold alloy). The nonporousnanoparticles (core is sliver；shell is silver/gold alloy) incorporated into nitrogen-enriched nanocarbons display an impressive electrocatalytic ORR performance. At 1600 rpm, it exhibits an ORR onset potential of about -0.1 V (v.s SCE) and the corresponding ORR current density (J) reaches around 4.8 mA/cm2. The transferred electron number (n) is 3.9. The reason is that the small size effects of gold nanoparticles (Au NPS) benefit activating oxygen molecules.

並列關鍵字

nitrogen-doping carbons ； metal-doping carbons ； oxygen reduction activity

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