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A facile method was developed in this work for the batch production of fibrous microelectrodes in enzyme-free electrochemical glucose sensors. The microelectrodes utilized carbon fibers (CFs) as the substrate and cobalt-containing metal organic framework, ZIF-67, as the electrocatalyst, which were mediated with reduced graphene oxide (rGO). The overall fabrication processes were carried out with carbon clothes and the fibrous ZIF-67/rGO/CF microelectrodes were extracted from the resulting composite, rendering a time-saving and economical batch-production approach. As the working electrode (WE) for electrochemical glucose detection, ZIF-67/rGO/CF manifested a wide linear detection range of 1–1000 μM, a low detection limit of 0.2 μM (S/N = 3), accompanied with the excellent selectivity and stability, which were comparable to the recently reported enzyme-free electrodes based on cobalt. A fibrous electrode based glucose sensor with ZIF-67/rGO/CF as the WE was further assembled, which showed reliable detection capability towards the glucose in serum and demonstrated the intriguing potential of ZIF-67/rGO/CF in practical applications. [ABSTRACT FROM AUTHOR]

A novel lyotropic liquid-crystal (LC) based assembly strategy is developed for the first time, to fabricate composite films of vanadium pentoxide (V2O5) nanobelts and graphene oxide (GO) sheets, with highly oriented layered structures. It is found that similar lamellar LC phases can be simply established by V2O5 nanobelts alone or by a mixture of V2O5 nanobelts and GO nanosheets in their aqueous dispersions. More importantly, the LC phases can be retained with any proportion of V2O5 nanobelts and GO, which allows facile optimization of the ratio of each component in the resulting films. Named VrGO, composite films manifest high electrical conductivity, good mechanical stability, and excellent flexibility, which allow them to be utilized as high performance electrodes in flexible energy storage devices. As demonstrated in this work, the VrGO films containing 67 wt% V2O5 exhibit excellent capacitance of 166 F g−1 at 10 A g−1; superior to those of the previously reported composites of V2O5 and nanocarbon. Moreover, the VrGO film in flexible lithium ion batteries delivers a high capacity of 215 mAh g−1 at 0.1 A g−1; comparable to the best V2O5 based cathode materials. [ABSTRACT FROM AUTHOR]

A composite of perylene diimide/reduced graphene oxide (PDI/RGO) is fabricated via a hit-and-run strategy in this work. In the hitting step, the ionic self-assembly of positively charged N,N′-bis(N-ethyl-N,N-dimethylhexan-1-aminium)perylene-3,4,9,10-tetracarboxylic diimide bromide (N + -PDI) and negative charged graphene oxide (GO) leads to the formation of the highly wrinkled composites (N + -PDI/RGOs) in solution. In the following running step to generate PDI/RGO, the composite of N + -PDI and solvothermally reduced GO is thermally treated at 300 °C to remove the ammonium groups in N + -PDI and further improve the conductivity. As the cathode in sodium ion battery (SIB), PDI/RGO delivers a specific capacity of ∼175 mA h g −1 at 50 mA g −1 even after 500 charge-discharge cycles and still maintains a capacity of ∼73 mA h g −1 at 800 mA g −1 , outperforming most of the state-of-art organic SIB cathodes. More importantly, the investigation on the changes of the composites during the fabrication processes enables the understanding of the influences of the morphology, crystallinity, and compositions on their electrochemical performances in SIB, which will be helpful for the design of high performance organic electrodes in secondary batteries. [ABSTRACT FROM AUTHOR]

In this work, leaf-like hybrid with Bi 2 O 2 CO 3 nanotubes as the “veins” and graphene sheet as the “laminae” is fabricated via a facile one-pot reaction of bismuth nitrate and graphene oxide in alkaline aqueous solution. With the uniform distribution of Bi 2 O 2 CO 3 nanotubes on the graphene substrate, the obtained Bi 2 O 2 CO 3 -NT/G manifests high specific surface area (90.4 m 2 g −1 ) and large pore volume (0.197 cm 3 g −1 ), which are favorable for the efficient light capturing together with the rapid transfer of mass and charge carriers. In comparison with the pure Bi 2 O 2 CO 3 nanotubes and commercial Bi 2 O 2 CO 3 , Bi 2 O 2 CO 3 -NT/G exhibits much enhanced activity and long-term stability towards the photocatalytic degradation of organic dye pollutant, which is owing to its unique leaf-like structural features. [ABSTRACT FROM AUTHOR]