Bismuth oxycarbonate Nanoplates@α-Ni(OH)₂ nanosheets 2D plate-on-sheet heterostructure as electrode for high-performance supercapacitor

In the development of better-architectures in nanomaterials for energy storage devices, heterostructures have played an important role. In this paper, we have reported a new class of nanocomposite with two-dimensional plate-on-sheet heterostructure Bi₂O₂CO₃ nanoplates@α-Ni(OH)₂ nanosheets (BCNP@NHNS) based nanocomposite was synthesized via a simple one-pot hydrothermal approach. The fabricated BCNP@NHNS plate-on-sheet heterostructure exhibit better cyclic performance with higher specific capacitance than those of pristine Bi₂O₂CO₃ and α-Ni(OH)₂. The optimized electrodes delivered a high specific capacity up to 743 F g⁻¹ at an applied current density of 3 A g⁻¹. Further, fabricated two-electrode symmetric supercapacitor (SSC) with KOH aqueous electrolyte delivered an energy density of 73.7 Wh kg⁻¹ coupled with a power density of 872.7 W kg⁻¹ and high capacitance of 725 F g⁻¹ at a current density of 1 A g⁻¹. The retention of specific capacity up to 92.8% was achieved after 5000 cycles. The superior performance of BCNP@NHNS nanocomposite as a potential electrode material for supercapacitors with long cycling life is owed to the synergetic effect of the heterostructure in the nanocomposite.