Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
J Am Chem Soc. 2013 Jul 17;135(28):10274-7. doi: 10.1021/ja404523s. Epub 2013 Jul 3.
Promising catalytic activity from molybdenum disulfide (MoS2) in the hydrogen evolution reaction (HER) is attributed to active sites located along the edges of its two-dimensional layered crystal structure, but its performance is currently limited by the density and reactivity of active sites, poor electrical transport, and inefficient electrical contact to the catalyst. Here we report dramatically enhanced HER catalysis (an electrocatalytic current density of 10 mA/cm(2) at a low overpotential of -187 mV vs RHE and a Tafel slope of 43 mV/decade) from metallic nanosheets of 1T-MoS2 chemically exfoliated via lithium intercalation from semiconducting 2H-MoS2 nanostructures grown directly on graphite. Structural characterization and electrochemical studies confirmed that the nanosheets of the metallic MoS2 polymorph exhibit facile electrode kinetics and low-loss electrical transport and possess a proliferated density of catalytic active sites. These distinct and previously unexploited features of 1T-MoS2 make these metallic nanosheets a highly competitive earth-abundant HER catalyst.
二硫化钼 (MoS2) 在析氢反应 (HER) 中具有很有前景的催化活性，这归因于其二维层状晶体结构边缘的活性位点，但它的性能目前受到活性位点的密度和反应性、较差的电子输运以及与催化剂之间的低效电子接触的限制。在这里，我们报告了通过直接在石墨上生长的半导体 2H-MoS2 纳米结构中的锂离子插层化学剥离的 1T-MoS2 金属纳米片，HER 催化活性得到了显著增强（在低过电势 -187 mV 相对于 RHE 时的电流密度为 10 mA/cm2，塔菲尔斜率为 43 mV/decade）。结构表征和电化学研究证实，这种金属 MoS2 多晶型的纳米片具有简便的电极动力学和低损耗的电子输运，并具有增殖的催化活性位点密度。1T-MoS2 的这些独特且以前未被开发的特性使其成为一种极具竞争力的富含地球的 HER 催化剂。
