A Janus cobalt-based catalytic material for electro-splitting of water
A Janus cobalt-based catalytic material for electro-splitting of water
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DOI：
10.1038/nmat3385
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发表时间：
2012-09-01
期刊：
影响因子：
41.2
通讯作者：
Artero, Vincent
中科院分区：
文献类型：
--
作者：
Cobo, Saioa;Heidkamp, Jonathan;Artero, Vincent
能源供应的未来取决于在设计廉价、可持续和高效的可再生能源转换和储存系统方面的创新突破。通过水裂解生产氢气似乎是一个有前途和吸引力的解决方案。我们发现，一个强大的纳米颗粒电催化材料，H-2-CoCat，可以电化学制备钴盐在磷酸盐缓冲液。该材料由金属钴组成，涂覆有与电解质接触的钴-氧代/羟基-磷酸盐层，并在适度的过电位下介导中性水性缓冲液中的H-2释放。值得注意的是，它可以在阳极平衡时转化为先前描述的催化O-2释放的无定形钴氧化物膜（O-2-CoCat或CoPi）。两种催化形式之间的切换是完全可逆的，并且对应于电极表面处的两种形态和组合物之间的局部相互转化。在沉积之后，不含贵金属的涂层因此用作稳健的、双功能的和可切换的催化剂。
The future of energy supply depends on innovative breakthroughs regarding the design of cheap, sustainable and efficient systems for the conversion and storage of renewable energy sources. The production of hydrogen through water splitting seems a promising and appealing solution. We found that a robust nanoparticulate electrocatalytic material, H-2-CoCat, can be electrochemically prepared from cobalt salts in a phosphate buffer. This material consists of metallic cobalt coated with a cobalt-oxo/hydroxo-phosphate layer in contact with the electrolyte and mediates H-2 evolution from neutral aqueous buffer at modest overpotentials. Remarkably, it can be converted on anodic equilibration into the previously described amorphous cobalt oxide film (O-2-CoCat or CoPi) catalysing O-2 evolution. The switch between the two catalytic forms is fully reversible and corresponds to a local interconversion between two morphologies and compositions at the surface of the electrode. After deposition, the noble-metal-free coating thus functions as a robust, bifunctional and switchable catalyst.