Search

Abstract: SiBON fiber precursor was successfully synthesized through sol–gel method when distilled water was used as solvent, boric acid (H3BO3), melamine (C3H6N6) and tetraethoxysilane (TEOS) were used as raw materials. The precursor was nitrogenized in N2 at 1400–1800°C to prepare SiBON fiber. The chemical bonds structure, the micrograph and the elemental distribution of SiBON fiber have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and infrared spectroscopy (FTIR). The results showed: (1) the best nitrogenization temperature of SiBON fiber precursor was 1800°C; (2) SiBON fiber was amorphous materials of nitrides containing a small quantity of SiO2 and BN crystals; (3) bonds of BN, BOSi, BNSi and SiOSi existed in the SiBON fiber. [Copyright &y& Elsevier]

Uniform Co 3 O 4 @MoO 2 nanosheet arrays is fabricated through hydrothermal and electrodeposition method by virtue of the chemical-etching method. The electrochemical measurements show that the specific capacitance of 600 F g −1 at a scan rate of 2 mV s −1 for the Co 3 O 4 @MoO 2 hybrid is higher than both pristine MoO 2 and Co 3 O 4 . Moreover, the hybrid electrode with low resistance displays good cyclic stability of 83% retention after 1000-cycle charge/discharge. These results indicate that the as-prepared Co 3 O 4 @MoO 2 hybrid is a potential candidate used as electrode material in supercapacitors. [ABSTRACT FROM AUTHOR]

NiO with different morphologies were fabricated via hydrothermal method in different kinds of solvent. The morphology of the obtained NiO samples varied from nanoflakes to nanoparticles with the different volume ratios of water to ethanol. The electrochemical results showed that the specific capacitance of NiO-S5 obtained in ethanol was up to 1337.5 F g −1 at a current density of 0.62 A g −1 , which was greatly higher than that of the other samples. These results indicated that NiO-S5 had the superior electrochemical behavior which may be due to its small-size effect. [ABSTRACT FROM AUTHOR]

Hexagonal-MoO 3 /polypyrrole conductive hybrid is facilely prepared by wrapping a homogenous polypyrrole (PPy) layer around hexagonal-MoO 3 ( h -MoO 3 ) prism via in-situ oxidative polymerization of self-assembled pyrrole monomer. The electrochemical performance of the obtained h -MoO 3 /PPy hybrid in different electrolytes is investigated. The cyclic voltammogram results at different scan rates show that the rate behaviors of h -MoO 3 /PPy in the three electrolytes improve in the order of Li 2 SO 4 < Na 2 SO 4 < K 2 SO 4 . The EIS measurement indicates that the h -MoO 3 /PPy hybrid in K 2 SO 4 electrolyte exhibits lower charge-transfer resistance and equivalent series resistance, which attributes to the small hydrated ionic radius and fast transfer rate of K + . Furthermore, the cycling stability of the h -MoO 3 /PPy hybrid also increase in the sequence of Li 2 SO 4 < Na 2 SO 4 < K 2 SO 4 . The above results provide valuable supporting information to explore new hybrid supercapacitor system. [ABSTRACT FROM AUTHOR]