3 research outputs found

    Controllable Growth of CNTs on Graphene as High-Performance Electrode Material for Supercapacitors

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    Design and synthesis of three-dimensional (3D) structured carbon materials are crucial for achieving high-performance supercapacitors (SC) for energy storage. Here, we report the preparation of 3D architectured GN-CNT hybrid as SC electrodes. Controllable growth of carbon nanotubes on graphene sheets was realized through a facile one-pot pyrolysis strategy. The length of the carbon nanotubes could be rationally tuned by adjusting the amount of precursors. Correspondingly, the resulted GN-CNT hybrid showed adjustable electrochemical performance as an SC electrode. Importantly, the GN-CNT exhibited a high specific surface area of 903 m<sup>2</sup> g<sup>–1</sup> and maximum specific capacitance of 413 F g<sup>–1</sup> as SC electrodes at a scan rate of 5 mV s<sup>–1</sup> in 6 M KOH aqueous solution. This work paves a feasible pathway to prepare carbon electrode materials with favorable 3D architecture and high performance, for use in energy storage and conversion

    Built-in Electric Field-Induced Work Function Reduction in C–Co<sub>3</sub>O<sub>4</sub> for Efficient Electrochemical Nitrogen Reduction

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    Co3O4 is a highly selective catalyst for the electrochemical conversion of N2 to NH3. However, the large work function (WF) of Co3O4 leads to unsatisfactory activity. To address this issue, a strong built-in electric field (BIEF) was constructed in Co3O4 by doping C atoms (C–Co3O4) to reduce the WF for improving the electrocatalytic performance. C–Co3O4 exhibited a remarkable NH3 yield of 38.5 μg h–1 mgcat–1 and a promoted FE of 15.1% at −0.3 V vs RHE, which were 2.2 and 1.9 times higher than those of pure Co3O4, respectively. Kelvin probe force microscopy (KPFM), zeta potential, and ultraviolet photoelectron spectrometry (UPS) confirmed the formation of strong BIEF and WF reduction in C–Co3O4. Additionally, in situ Raman measurements and density functional theory (DFT) calculations revealed the relationship between BIEF and WF and provided insights into the reaction mechanism. Our work offers valuable guidance for the design and development of more efficient nitrogen reduction catalysts
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