Browsing by Author "Zhao, Fenglin"

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    Construction of porous hierarchical NiCo2S4 toward high rate performance supercapacitor
    (Springer, 2019-11-11) Zhao, Fenglin; Huang, Wanxia; Sial, Muhammad Aurang Z. G.; Xie, Dong; Wu, Hongliang; Zhang, Qi; Zou, Jizhao; Zeng, Xierong
    Developing high-performance supercapacitors is an effective way to satisfy the ever-increasing energy storage demand for emerging devices, but the inferior rate performance of battery-type supercapacitors limits their large-scale utilization. Herein, porous hierarchical nickel cobalt sulfide (NiCo2S4) was constructed by a novel strategy that the synthesized nickel cobalt oxide nanosheets as chemical template for hydrothermal method. Furthermore, the backbone of nickel cobalt oxide nanosheets can finally convert to NiCo2S4, which both plays the role of matrix to buffer the volume variation and enhances entire conductivity. Benefiting from high specific area (79.9 m2 g−1), suitable nanopores for KOH electrolyte, high conductivity, and multiple Co/Ni valence, the hierarchical NiCo2S4 electrode delivers a high specific capacity of 1035.1 F g−1 at the current density of 1 A g−1, and an ultrahigh rate performance of 80.9% capacitance retention at 20 A g−1 was obtained. The assembled asymmetric supercapacitor device could achieve the maximum capacity of 102.4 F g−1 at 5 mV s−1 and maintain at 80.5 F g−1 at 50 mV s−1, indicating its superior rate ability. In addition, the highest energy density of 35.4 Wh kg−1 can be obtained at a power density of 0.4 kW kg−1. These results indicate that the porous hierarchical NiCo2S4 could be served as high rate performance electrode materials for advanced supercapacitors.
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    CoSe2/Co nanoheteroparticles embedded in Co, Nco-doped carbon nanopolyhedra/nanotubes as anefficient oxygen bifunctional electrocatalyst for Zn–air batteries
    (Royal Society of Chemistry, 2020-06-30) Zou, Jizhao; Luo, Qi; Wu, Hongliang; Liu, Shiyu; Lan, Tongbin; Yao, Yuechao; Sial, Muhammad Aurang Zeb Gul; Zhao, Fenglin; Zhang, Qi; Zenga, Xierong
    Transition metal selenide-based materials have been demonstrated as promising electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), yet the actual design of a highly efficient and stable electro-catalyst based on these materials still remains a long and arduous challenge. Herein, a predesigned hybrid Zn/Co zeolitic imidazole framework was used to fabricate CoSe2/Co nanoheteroparticles embedded within hierarchically porous Co, N co-doped carbonnanopolyhedra/nanotubes (CoSe2/Co@NC-CNTs) through a facile approach involving controlled carbonization and selenization procedures. As expected, the optimized CoSe2/Co@NC-CNT-1 displayed outstanding electrocatalytic performance for the ORR and OER, with an onset potential of 0.95 V vs. RHE, a half-wave potential of 0.84 V vs. RHE for ORR, and a potential of 1.69 V vs. RHE for OER at 10 mA cm−2. It also exhibited excellent long-term stability and methanol resistance ability, which were superior to commercial IrO2 and the commercial 20 wt% Pt/C catalyst. Notably, the assembled Zn–air battery with CoSe2/Co@NC-CNT-1 showed a low charge–discharge voltage gap (0.696 V at 10 mA cm−2) and a high peak power density (100.28 mW cm−2) with long-term cycling stability. These superior performances can be ascribed to the synergistic effects of the highly active CoSe2/Co nanoheterostructure, hierarchically porous structure with a large surface area, high electrical conductivity and uniform doping of the Co and N