Synthesis of porous NiS nanoflake arrays by ion exchange reaction from NiO and their high performance supercapacitor properties

•NiS nanoflake arrays are prepared via an ion exchange method.•Nanoflake arrays are favorable for fast ion/electron transfer.•NiS nanoflake arrays show good supercapacitor performance.

Metal sulfides have emerged as a new class of promising active material for supercapacitors. Porous NiS nanoflake arrays are successfully synthesized by a facile solution-based ion exchange reaction (IER) method based on preformed chemical bath deposition (CBD) derived NiO nanoflake arrays. NiS nanoflake arrays preserve the morphology of precursor-NiO nanoflake arrays and grow vertically to the substrates. As cathode of supercapacitors, NiS nanoflake arrays exhibit outstanding electrochemical performances with a high specific capacitance of 718 F g−1 at 2 A g−1 and good cycle performance and capacity retention (593 F g−1 after 3000 cycles at 2 A g−1).

Graphical AbstractIon-exchange-synthesized NiS film exhibits porous structure composed of nanoflakes and high supercapacitor performance.Figure optionsDownload full-size imageDownload as PowerPoint slide