Department of Material Sciences and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
Nanoscale. 2018 Mar 15;10(11):5054-5059. doi: 10.1039/c7nr09042k.
A wafer-scale 1.4 nm ultrathin Ni(OH) nanosheet was synthesized by ionic layer epitaxy. This free-standing Ni(OH) nanosheet was directly used to catalyze the oxygen evolution reaction (OER). At a current density of 10 mA cm, the overpotential reached 295 mV (vs. RHE) in Fe-rich 1 M NaOH. This 1.4 nm Ni(OH) nanosheet showed a very high turnover frequency of 5.47 s and a mass activity of more than 2 × 10 A g at an overpotential of 300 mV. Such a high electrocatalytic mass activity of the Ni(OH) nanosheet was more than 2 orders of magnitude higher than those of typical OER catalysts. The capability of producing wafer-scale nanometer-thick nanosheets offers a promising strategy to improve the mass efficiency of electrochemical catalysts, which is particularly valuable for preserving rare and precious catalyst materials.
通过离子层外延法合成了晶圆级 1.4nm 超薄 Ni(OH)纳米片。这种独立的 Ni(OH)纳米片可直接用于催化析氧反应（OER）。在富铁的 1M NaOH 中，电流密度为 10mA cm 时，过电位达到 295 mV（相对于 RHE）。这种 1.4nm Ni(OH)纳米片在 300 mV 的过电位下具有非常高的周转频率 5.47 s 和超过 2×10 A g 的质量活性。这种 Ni(OH)纳米片的高电催化质量活性比典型的 OER 催化剂高出 2 个数量级以上。生产晶圆级纳米厚纳米片的能力为提高电化学催化剂的质量效率提供了一种很有前途的策略，这对于保存稀有和珍贵的催化剂材料尤其有价值。
