Ultrathin mesoporous F-doped -Ni(OH)2 nanosheets as an efficient electrode material for water splitting and supercapacitors

Two-dimensional (2D) nanomaterials with a high specific surface area and mesoporous nature are attractive and have wide applications in catalysis, energy storage systems, etc. Here, we report a novel strategy to fabricate noble metal-free, F-doped -Ni(OH)(2) mesoporous 2D ultrathin nanosheets. The F-doped -Ni(OH)(2) nanosheets exhibit remarkable electrocatalytic activity and stability for the oxygen evolution reaction, achieving a low onset potential (260 mV), high mass activity (69.1 A g(-1) at = 350 mV) and low Tafel slope (31.89 mV dec(-1)), which are superior to those of commercial RuO2 catalysts. Simultaneously, F-doped -Ni(OH)(2) nanosheets are found to have a high specific capacitance of 158.75 F g(-1) at 1 A g(-1) with a maximum energy density of 67.4 W h kg(-1) at a power density of 400 W kg(-1), which could still retain 40 W h kg(-1) at a power density of 16 kW kg(-1). DFT calculations rationalize that F doped -Ni(OH)(2) favors electrical conductivity, efficient electron transport and water adsorption. It could be envisioned that the proposed simple and efficient approach will pave a new way to synthesize other anion doped 2D materials for energy conversion and storage technology.