One-Step Synthesis of NiMn-Layered Double Hydroxide Nanosheets Efficient for Water Oxidation

Layered double hydroxides (LDHs) are noble metal-free 2D materials promising for water oxidation. One-step synthesis of ultrathin NiMn-LDHs nanosheets is successfully achieved at room temperature avoiding the multiple tedious steps (e.g., hydrothermal treatment, exfoliation). The as-prepared NiMn-LDHs (1.3 nm thickness) exhibit the twofold enhancement of the activity and a reduction of overpotential by 80 mV at 10 mA cm(-2) in comparison with the traditional NiMn-LDHs in 0.1 m NaOH, which is superior to the previously reported LDH-derived electrocatalysts. The combination of theoretical and experimental results manifest that the largely enhanced electrocatalytic water oxidation activity of NiMn-LDHs nanosheets is associated with the highly exposed active sites with a nearly optimal intermediates (*OH and *O) adsorption energy.