Kim Jin Koo, Park Gi Dae, Kim Jung Hyun, Park Seung-Keun, Kang Yun Chan
Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul, 136-713, Republic of Korea.
Small. 2017 Jul;13(27). doi: 10.1002/smll.201700068. Epub 2017 May 30.
Uniquely structured CoSe -carbon nanotube (CNT) composite microspheres with optimized morphology for the hydrogen-evolution reaction (HER) are prepared by spray pyrolysis and subsequent selenization. The ultrafine CoSe nanocrystals uniformly decorate the entire macroporous CNT backbone in CoSe -CNT composite microspheres. The macroporous CNT backbone strongly improves the electrocatalytic activity of CoSe by improving the electrical conductivity and minimizing the growth of CoSe nanocrystals during the synthesis process. In addition, the macroporous structure resulting from the CNT backbone improves the electrocatalytic activity of the CoSe -CNT microspheres by increasing the removal rate of generated H and minimizing the polarization of the electrode during HER. The CoSe -CNT composite microspheres demonstrate excellent catalytic activity for HER in an acidic medium (10 mA cm at an overpotential of ≈174 mV). The bare CoSe powders exhibit moderate HER activity, with an overpotential of 226 mV at 10 mA cm . The Tafel slopes for the CoSe -CNT composite and bare CoSe powders are 37.8 and 58.9 mV dec , respectively. The CoSe -CNT composite microspheres have a slightly larger Tafel slope than that of commercial carbon-supported platinum nanoparticles, which is 30.2 mV dec .
通过喷雾热解和后续硒化制备了具有独特结构、用于析氢反应（HER）的形态优化的CoSe-碳纳米管（CNT）复合微球。在CoSe-CNT复合微球中，超细的CoSe纳米晶体均匀地装饰在整个大孔CNT骨架上。大孔CNT骨架通过提高电导率并在合成过程中最小化CoSe纳米晶体的生长，极大地提高了CoSe的电催化活性。此外，由CNT骨架产生的大孔结构通过提高生成的H的去除率并在HER过程中最小化电极的极化，提高了CoSe-CNT微球的电催化活性。CoSe-CNT复合微球在酸性介质中对HER表现出优异的催化活性（在过电位约为174 mV时为10 mA cm）。裸CoSe粉末表现出中等的HER活性，在10 mA cm时过电位为226 mV。CoSe-CNT复合材料和裸CoSe粉末的塔菲尔斜率分别为37.8和58.9 mV dec。CoSe-CNT复合微球的塔菲尔斜率比商业碳载铂纳米颗粒的塔菲尔斜率略大，后者为30.2 mV dec。
