Serrà Albert, Montiel Manuel, Gómez Elvira, Vallés Elisa
Physical Chemistry Department and Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.
Nanomaterials (Basel). 2014 Mar 28;4(2):189-202. doi: 10.3390/nano4020189.
A new electrochemical method to synthesize mesoporous nanowires of alloys has been developed. Electrochemical deposition in ionic liquid-in-water (IL/W) microemulsion has been successful to grow mesoporous CoPt nanowires in the interior of polycarbonate membranes. The viscosity of the medium was high, but it did not avoid the entrance of the microemulsion in the interior of the membrane's channels. The structure of the IL/W microemulsions, with droplets of ionic liquid (4 nm average diameter) dispersed in CoPt aqueous solution, defined the structure of the nanowires, with pores of a few nanometers, because CoPt alloy deposited only from the aqueous component of the microemulsion. The electrodeposition in IL/W microemulsion allows obtaining mesoporous structures in which the small pores must correspond to the size of the droplets of the electrolytic aqueous component of the microemulsion. The IL main phase is like a template for the confined electrodeposition. The comparison of the electrocatalytic behaviours towards methanol oxidation of mesoporous and compact CoPt nanowires of the same composition, demonstrated the porosity of the material. For the same material mass, the CoPt mesoporous nanowires present a surface area 16 times greater than compact ones, and comparable to that observed for commercial carbon-supported platinum nanoparticles.
一种合成合金介孔纳米线的新型电化学方法已被开发出来。在水包离子液体（IL/W）微乳液中进行电化学沉积已成功地在聚碳酸酯膜内部生长出介孔CoPt纳米线。介质的粘度很高，但这并未阻止微乳液进入膜通道内部。IL/W微乳液的结构，即离子液体液滴（平均直径4纳米）分散在CoPt水溶液中，决定了纳米线的结构，其具有几纳米的孔隙，这是因为CoPt合金仅从微乳液的水相成分中沉积。在IL/W微乳液中的电沉积能够获得介孔结构，其中小孔隙必定与微乳液的电解水相成分液滴的尺寸相对应。IL主相就像是受限电沉积的模板。对相同组成的介孔和致密CoPt纳米线对甲醇氧化的电催化行为进行比较，证明了材料的孔隙率。对于相同质量的材料，CoPt介孔纳米线的表面积比致密纳米线大16倍，与商业碳载铂纳米颗粒的表面积相当。
