Uniformly Dispersed ZnFe 2 O 4 Nanoparticles on Nitrogen-Modified Graphene for High-Performance Supercapacitor as Electrode.

A facile strategy has been adopted for the preparation of ZnFe2 O4 /NRG composite by anchoring ultrasmall ZnFe2 O4 nanoparticles on nitrogen-doped reduced graphene (denoted as NRG) for high-performance supercapacitor electrode. Remarkably, the growth of ZnFe2 O4 nanocrystals, the reduction of graphitic oxide and the doping of nitrogen to graphene have been simultaneously achieved in one process. It is found that the NRG employed as substrate can not only control the formation of nano-sized ZnFe2 O4 , but also guarantee the high dispersion without any agglomeration. Benefiting from this novel combination and construction, the hybrid material has large surface area which can provide high exposure of active sites for easy access of electrolyte and fast electron transport. When served as supercapacitor electrode, the ZnFe2 O4 /NRG composite exhibits a favorable specific capacitance of 244 F/g at 0.5 A/g within the potential range from -1 to 0 V, desirable rate stability (retain 131.5 F/g at 10 A/g) and an admirable cycling durability of 83.8% at a scan rate of 100 mV/s after 5000 cycles. When employed as symmetric supercapacitor, the device demonstrates favorable performance. These satisfactory properties of the ZnFe2 O4 /NRG composite can make it be of great promise in the supercapacitor application.