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Three-dimensional (3D) graphene aerogel and its composite with interconnected pores have aroused continuous interests in energy storage field owning to its large surface area and hierarchical pore structure. Herein, we reported the preparation of 3D nitrogen-doped graphene/polyaniline (N-GE/PANI) composite foam for supercapacitive material with greatly improved electrochemical performance. The 3D porous structure can allow the penetration and diffusion of electrolyte, the incorporation of nitrogen doping can enhance the wettability of the active material and the number of active sites with electrolyte, and both the N-GE and PANI can ensure the high electrical conductivity of total electrode. Moreover, the synergistic effect between N-GE and PANI materials also play an important role on the electrochemical performance of electrode. Therefore, the as-prepared composite foam could deliver a high specific capacitance of 528 F g −1 at 0.1 A g −1 and a high cyclic stability with 95.9% capacitance retention after 5000 charge-discharge cycles. This study provides a new idea on improving the energy storage capacity of supercapacitors by using 3D graphene-based psedocapacitive electrode materials. [ABSTRACT FROM AUTHOR]

The development of accurate, reliable and low cost devices for glucose detection is one of the most important scientific and technological hotspots. In this study, we proposed a unique one-step thermal synthesis strategy to synthesize nickel (Ni) nanoparticles modified graphene (GE) sheets by using metal-oleate complex as the precursor and sodium sulfate as a template. With the assistance of sodium sulfate particles, Ni nanoparticles with particle size of about 99.2 nm were homogenously anchored on graphene nanosheets in the product. The electrochemical behavior of the nanocomposite towards enzyme-free glucose oxidation was investigated systematically by cyclic voltammetry and amperometric measurements. The results reveal that the GE/Ni nanocomposite exhibited excellent electrocatalytic response to glucose with a wide linear range of 0.01–2.5 mM, a low detection limit of 0.79 μM, and a high sensitivity of 388.4 μA mM −1 cm −2 . In addition, no significant interference was observed from potential interference species. The simple, efficient and scalable synthesis and the excellent catalytic performance endow the GE/Ni nanocomposite great potential application in enzymeless glucose detection. [ABSTRACT FROM AUTHOR]