Porous graphene oxide nanosheets warped by Ni(OH)2 platelets as an efficient binder-free electrode material for supercapacitors

This article describes synthesis of the nickel hydroxide nanostructures (Ni(OH)2)@porous reduced graphene oxide (p-RGO) on 3-D nickel foam (NF) through a cost-effective one-step electrochemical strategy. This method composed of electrophoretic deposition of porous RGO plates and in situ formation of hydroxide nanostructures onto NF electrode. For comparison, the pristine Ni(OH)2/NF electrode was also fabricated via the similar method. The prepared nano-composite structure showed high surface area of 269.3 m(2) g(-1) with mesoporous texture and mean pore diameter of 3.58 nm, where the pure Ni hydroxide exhibited only surface area of 73.5 m(2) g(-1) and pore diameter of 2.75 nm. Both prepared samples were characterized via XRD, IR, FE-SEM, Raman, BET, TGA/DSC and TEM analyses. The nickel hydroxide@p-RGO composite deposited onto NF electrode has high specific capacitances as well as high electrical conductivity, where it delivered higher capacity of 1792 F g(-1) at a current load of 2 A g(-1) when compared with the Ni(OH)(2) electrode (1175 F g(-1) at the same current density), which nearly 65 % increment in capacity was observed. The composite material exhibited an outstanding capacity retention of similar to 95.3 % and 87.6 % after 4000 cycles at the current densities of 1 and 7 A g(-)1(,) respectively. This methodology provides a feasible route for preparation of the metal hydroxide/graphene hybrid materials for electrochemical energy storage applications.