Microwave Synthesis of Ultrathin Nickel Hydroxide Nanosheets with Iron Incorporation for Electrocatalytic Water Oxidation

Two-dimensional ultrathin nickel hydroxide nanosheets with large surface area and excellent electronic properties have been considered as promising electrocatalysts for the oxygen evolution reaction (OER). Herein, we report a facile microwave synthetic strategy to prepare ultrathin nickel hydroxide nanosheets with thickness <1 nm. In addition, varying the iron incorporation into the parent nickel hydroxide nanosheets allows us to synthesize a series of Ni1-xFex(OH)(2) nanosheets without sacrificing the atomic thickness. Electrochemical studies demonstrate that Fe0.22Ni0.78(OH)(2) nanosheets exhibit the best OER activity, requiring an overpotential of only 315 mV to achieve 10 mA/cm(2) plus strong robustness in 1.0 M KOH. The enhanced OER performance could be mainly attributed to the intrinsically more active sites in Fe0.22Ni0.78(OH)(2). Overall, our work presents a novel and facile approach to obtain ultrathin nanosheets of nickel/iron hydroxides as competent OER electrocatalysts. The microwave synthetic approach could be readily extended to prepare many other ultrathin oxides/hydroxides for various applications.