Batch fabrication of mesoporous boron-doped nickel oxide nanoflowers for electrochemical capacitors

Highlights: • A new facile liquid-phase method has been employed for synthesis boron-doped NiO nanoflowers. • The specific surface area of NiO is as high as 200 m² g⁻¹. • NiO nanoflowers exhibit a high specific capacitance of ∼1309 F g⁻¹ at a charge and discharge current density of 3 A g⁻¹. • NiO nanoflowers have excellent cycling ability and even after 2500 cycles there is no significant reduction in specific capacitance. - Abstract: Boron-doped nickel oxide (B-NiO) nanoflowers are prepared by simple thermal decomposition of nickel hydroxide. B-NiO is porous sphere with a diameter of about 400 nm. B-NiO nanoflowers are composed of approximately 30 nm nanoplates and the thickness of the nanosheets is approximately 3 nm. The specific surface area of the material is as high as 200 m² g⁻¹ and the pore size distribution curves of B-NiO has three typical peaks in the range of mesoporous (5 nm, 13 nm and 18 nm). As an electrode for supercapacitors, the crystalline B-NiO nanoflowers have favorable characteristics, for instance, a specific capacitance of 1309 F g⁻¹ at a current density of 3 A g⁻¹ and no significant reduction in Coulombic efficiency after 2500 cycles at 37.5 A g⁻¹. This remarkable electrochemical performance will make B-NiO nanoflowers a promising electrode material for high performance supercapacitors