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Abstract Despite many efforts devoted to explore novel electrode materials for lithium ion hybrid supercapacitors, the obtainable long-life cycling of existing anode materials are still inadequate for promising applications. This report demonstrates a new nanocomposite with TiNb 2 O 7 network nanostructure in situ anchored onto the holey graphene, which is designed as anode material for lithium ion hybrid supercapacitors. Impressively, electrochemical analyses show that the good rate performance (capacity retention of 73.5% from 0.05 to 5 A g−1) and long cycle life up to 1000 cycles at 1 A g−1 (a capacity retention of 91.5%) are attained. Furthermore, the lithium ion hybrid supercapacitor device consisting of this nanocomposite and activated carbon exhibits excellent cycling stability (90.2% of initial capacity after 3000 cycles), high energy density of 86.3 W h kg−1 (at 237.7 W kg−1) and high power density of 3.88 kW kg−1 (at 28.7 W h kg−1). This study ascribes the unprecedented performance to the high conductive holey graphene with abundant mesopores, the uniformly distributed TiNb 2 O 7 network nanostructure and the synergetic effect between them. Based on these findings, the presented nanocomposite has great potential in high performance lithium ion hybrid supercapacitors. Graphical abstract Image 1 Highlights • A novel composite of TiNb 2 O 7 network nanostructure and holey graphene was fabricated. • The long-term life with 91.5% capacity retention after 1000 cycles was obtained. • The Li-HSC device exhibits high energy density and excellent cycling stability. [ABSTRACT FROM AUTHOR]

Abstract: A novel high-performance electrode material based on fibrillar polyaniline (PANI) doped with graphene oxide sheets was synthesized via in situ polymerization of monomer in the presence of graphene oxide, with a high conductivity of 10Scm−1 at 22°C for the obtained nanocomposite with a mass ratio of aniline/graphite oxide, 100:1. Its high specific capacitance of 531F/g was obtained in the potential range from 0 to 0.45V at 200mA/g by charge–discharge analysis compared to 216F/g of individual PANI. The doping and the ratio of graphene oxide have a pronounced effect on the electrochemical capacitance performance of the nanocomposites. [Copyright &y& Elsevier]

Ultrafine CuS nanoparticles anchored on nitrogen-sulfur co-doped graphene nanosheets are synthesized by a simple-green solvothermal method, the composite has excellent electrochemical performance for CO 2 reduction. [Display omitted] • The CuS/N, S-rGO was synthesized via a facile and environmentally friendly method. • The co-doping of N and S on graphene can promote the activation and conversion of CO 2. • CuS/N, S-rGO exhibits outstanding formate selectivity for CO 2 RR. Electrochemical conversion of CO 2 into hydrocarbons can effectively alleviate the energy crisis and promote carbon cycle. Herein, we report that small-size CuS nanoparticles are confined in nitrogen and sulfur co-doped reduced graphene oxide (CuS/N,S-rGO) for electrochemically reducing CO 2 to formate. Specifically, the CuS/N,S-rGO electrode achieves maximum Faradaic efficiency of 82% for formate formation at −0.63 V versus the reversible hydrogen electrode (RHE). Moreover, this catalyst exhibits a stable performance during 20 h-electrolysis. Experiments demonstrate that the doping of nitrogen and sulfur can create an abundance of active sites on the graphene nanosheets to accelerate the CO 2 reduction reaction (CO 2 RR). The CuS/N,S-rGO electrode exhibits excellent performance for CO 2 RR is attributed to the synergistic effect between N,S-rGO and CuS, and graphene can improve stability of composite. This work provides an efficient electrocatalyst for CO 2 RR and offers a facile and environmental friendly approach to synthesize small-size Cu-based composites. [ABSTRACT FROM AUTHOR]