Facile Synthesis of Nitrogen-Doped Graphene Aerogels for Electrode Materials in Supercapacitors

Three-dimensional porous nitrogen-doped graphene aerogels （NGAs） were synthesized by using graphene oxide （GO） and chitosan （CS） via a self-assembly process by one-pot hydrothermal method. The morphology and struc- ture of the as-prepared materials were characterized by means of scanning electron microscopy, transmission elec- tron microscopy, X-ray diffraction, XPS spectroscopy, Raman spectroscopy, nitrogen adsorption/desorption meas- urement and Fourier transform infrared spectroscopy. The electrochemical performance of NGAs was studied by cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The microstructure, surface area and capacitance of NGAs could be facilely controlled by adding different amounts of chitosan. The prepared NGA-4 showed a specific capacitance of 148.0 F/g at the discharge current density of 0.5 A/g and also re- tained 95.3% of the initial capacitance after 5000 cycles at the scan rate of 10 mV/s. It provided a possible way to obtain graphene based materials with high surface area and capacitance.

Adhesive aero-hydrogel hybrid conductor assembled from silver nanowire architectures

Conductive and adhesive hydrogels are promising materials for designing bioelectronics.To satisfy the high conductivity of bioelectronic devices,metal nanomaterials have been used to fabricate composite hydrogels.However,the fabrication of a conductive-nanomaterial-incorporated hydrogel with high performance is a great challenge because of the easy aggregation nature of conductive nanomaterials making processing difficult.Here,we report a kind of adhesive aero-hydrogel hybrid conductor(AAHC)with stretchable,adhesive and anti-bacteria properties by in situ formation of a hydrogel network in the aerogel-silver nanowires(AgNWs)assembly.The AgNWs with good conductivity are wellintegrated on the inner-surface of shape-memory chitosan aerogel,which created a conductive framework to allow hydrogel back-filling.Reinforcement by the aerogel-silver makes the hybrid hydrogel tough and stretchable.Functional groups from the hydrogel allow strong adhesion to wet tissues through molecular stitches.The inherent bacteria-killing ability of silver ions endows the conductive hydrogel with excellent anti-bacteria performance.The proposed facile strategy of aerogel-assisted assembly of metal nanomaterials with hydrogel opens a new route to incorporate functional nanoscale building blocks into hydrogels.