Preparation and Electrochemical Characterization of Carbon Paper Modified with a Layer of Boron-Doped Nanocrystalline Diamond
Preparation and Electrochemical Characterization of Carbon Paper Modified with a Layer of Boron-Doped Nanocrystalline Diamond
复制标题
掺硼纳米晶金刚石改性碳纸的制备及电化学表征
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
G. Swain
中科院分区：
文献类型：
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作者：
A. Fischer;Michael A. Lowe;G. Swain
碳纸（CP）改性与硼掺杂的纳米金刚石（BND）层，以提高材料的耐化学性和微观结构的稳定性，在暴露于腐蚀性电化学环境。在该过程中，CP中的碳纤维被涂覆到约50 μm的深度，具有薄层（约100 μ m）。1 μm）的导电金刚石。采用微波等离子体辅助化学气相沉积技术，以富氩的CH 4 /H2/Ar/B 2 H6混合气体为源气体，制备了金刚石薄膜。X射线衍射和拉曼光谱证实了结晶金刚石覆盖层的存在。Pt电催化剂颗粒的电沉积被用来探测金刚石涂层电极的电化学活性。使用脉冲恒电流沉积（阴极）在1.25mA/cm 2（几何）下形成金属相。并根据（i）粒度和分布、（ii）阳极极化期间的稳定性和（iii）还原溶解氧的电化学活性进行评价。在BND电极的所有区域上形成了直径为100-300 nm、颗粒密度为10 8 - 10 9 cm-2的Pt颗粒。重要的是，金刚石修饰电极在阳极极化（1.4 V vs Ag/AgCl）过程中表现出上级的形态和微观结构的稳定性相比，CP，在存在和不存在的Pt。结果表明，用导电金刚石进行表面改性是提高sp2碳材料尺寸稳定性的一种手段，特别是用于燃料电池的sp2碳材料。
Carbon paper (CP) was modified with a layer of boron-doped nanocrystalline diamond (BND) in order to improve the material's chemical resistance and microstructural stability during exposure to aggressive electrochemical environments. In the procedure, carbon fibers in the CP were coated up to a depth of about 50 μm with a thin layer (ca. 1 μm) of electrically conducting diamond. The diamond layer was deposited by microwave plasma-assisted chemical vapor deposition using an argon-rich CH 4 /H 2 /Ar/B 2 H 6 source gas mixture. X-ray diffraction and Raman spectroscopy confirmed the presence of a crystalline diamond overlayer. The electrodeposition of Pt electrocatalyst particles was used to probe the electrochemical activity of the diamond-coated electrode. The metal phase was formed using pulsed galvanostatic deposition (cathodic) at 1.25 mA/cm 2 (geom.) and evaluated in terms of (i) the particle size and distribution, (ii) the stability during anodic polarization, and (iii) the electrochemical activity for the reduction of dissolved oxygen. Pt particles with a diameter of 100-300 nm and a particle density of 10 8 -10 9 cm -2 were formed on all regions of the BND electrode. Importantly, the diamond-modified electrode exhibited superior morphological and microstructural stability during anodic polarization (1.4 V vs Ag/AgCl) as compared to CP, both in the presence and absence of Pt. The results demonstrate that surface modification with electrically conducting diamond is a means to improve the dimensional stability of sp 2 carbon materials, particularly those used in fuel cells.