Graphene homogeneously anchored with Ni(OH)2 nanoparticles as advanced supercapacitor electrodes

Abstract

A green and facile approach was demonstrated to prepare graphene nanosheet/Ni(OH)₂ (GNS/Ni(OH)₂) composites for supercapacitor materials. GNSs as a support material can offer moderate active sites for the nucleation of Ni(OH)₂, as well as an excellent electron transfer path. Then, ultrafine Ni(OH)₂ nanoparticles were homogeneously anchored onto the surface of GNSs as spacers to ensure the high electrochemical utilization of the graphene layers and supply the open nano-channels for shortening the ion diffusion pathway. The results show that the GNS/Ni(OH)₂ composites exhibit a superior specific capacitance of 1985.1 F g⁻¹ and excellent cycle life with a loss of specific capacitance of only 6.5% after 500 cycles. The improved high electrochemical performance is attributed to the increased electrode conductivity in the presence of the graphene network and the increased effective interfacial area caused by the well-dispersed Ni(OH)₂ on the GNSs.