High-Efficiency Electrochemical Hydrogen Evolution Based on Surface Autocatalytic Effect of Ultrathin 3C-SiC Nanocrystals
High-Efficiency Electrochemical Hydrogen Evolution Based on Surface Autocatalytic Effect of Ultrathin 3C-SiC Nanocrystals
复制标题
基于超薄3C-SiC纳米晶表面自催化效应的高效电化学析氢
DOI：
10.1021/nl3006947
复制
发表时间：
2012-03-01
期刊：
影响因子：
10.8
通讯作者：
Chu, Paul K.
中科院分区：
文献类型：
--
作者：
He, Chengyu;Wu, Xinglong;Chu, Paul K.
Good understanding of the reaction mechanism in the electrochemical reduction of water to hydrogen is crucial to renewable energy technologies. Although previous studies have revealed that the surface properties of materials affect the catalytic reactivity, the effects of a catalytic surface on the hydrogen evolution reaction (HER) on the molecular level are still not well understood. Contrary to general belief, water molecules do not adsorb onto the surfaces of 3C-SiC nanocrystals (NCs), but rather spontaneously dissociate via a surface autocatalytic process forming a complex consisting of -H and -OH fragments. In this study, we show that ultrathin 3C-SiC NCs possess superior electrocatalytic activity in the HER. This arises from the large reduction in the activation barrier on the NC surface enabling efficient dissociation of H2O molecules. Furthermore, the ultrathin 3C-SiC NCs show enhanced HER activity in photoelectrochemical cells and are very promising to the water splitting based on the synergistic electrocatalytic and photoelectrochemical actions. This study provides a molecular-level understanding of the HER mechanism and reveals that NCs with surface autocatalytic effects can be used to split water with high efficiency thereby enabling renewable and economical production of hydrogen.
