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Highlights: [•] Heteroatom doped mesoporous carbon/graphene (HMCG) were fabricated by nano-casting technology. [•] In HMCGs, graphene is sandwiched in two heteroatom-doped mesoporous carbon layers. [•] HMCGs exhibited excellent electrochemical performance for the oxygen reduction reaction. [Copyright &y& Elsevier]

Heteroatom doping is an effective method to adjust the electrochemical behavior of carbonaceous materials. In this work, boron-doped, carbon-coated SnO2/graphene hybrids (BCTGs) were fabricated by hydrothermal carbonization of sucrose in the presence of SnO2/graphene nanosheets and phenylboronic acid or boric acid as dopant source and subsequent thermal treatment. Owing to their unique 2D core-shell architecture and B-doped carbon shells, BCTGs have enhanced conductivity and extra active sites for lithium storage. With phenylboronic acid as B source, the resulting hybrid shows outstanding electrochemical performance as the anode in lithium-ion batteries with a highly stable capacity of 1165 mA h g−1 at 0.1 A g−1 after 360 cycles and an excellent rate capability of 600 mA h g−1 at 3.2 A g−1, and thus outperforms most of the previously reported SnO2-based anode materials. [ABSTRACT FROM AUTHOR]

The design versatility and performance advantages render supercapacitors (SCs) the highly appealing candidates for the energy storage units in flexible devices. For this purpose, a flexible electrode with high capacitance and excellent mechanical stability is essential. Herein, the facile fabrication strategy towards flexible SC electrodes with polyaniline (PANI) nanowires loading on nitrogen-doped carbon coated SS mesh (PANI/N-C/SS) is developed via a simple hydrothermal carbonization process and the following deposition of PANI. Derived from glucose and dicyandiamide, the nitrogen-doped carbon layer can effectively improve the contract of the SS substrate and PANI. The resultant PANI/N-C/SS electrode delivers a high areal capacitance of 624 mF cm −2 at 0.05 mA cm −2 . With a large size of 40 cm 2 , the solid-state symmetric capacitor based on PANI/N-C/SS still possesses a capacitance of 122.6 mF cm −2 , corresponding to a high energy density of 0.22 mWh cm −2 . [ABSTRACT FROM AUTHOR]

Hierarchically porous hybrids of strongly coupled nitrogen-doped porous carbons and graphene aerogel (NPC-GA) are fabricated through the solid-state oxidation polymerization and carbonization of m -phenylenediamine on the interconnected macroporous frameworks of GA. The hierarchically porous hybrids provide abundant storage sites and short transport paths for electrolyte ions. By adjusting the pyrolysis temperature, the specific surface areas and nitrogen content of NPC-GA can be easily modified, further influencing the electrochemical performance of the hybrids. In a three-electrode system, NPC-GA electrode shows high specific capacitance of 608 F g −1 at 0.1 A g −1 in 1 M H 2 SO 4 . An all-solid-state flexible supercapacitor based on NPC-GA delivers superior energy density (12.4 Wh Kg −1 ) and power density (2432 W Kg −1 ) as well as good cycling stability (92% specific capacitance retention after 10 000 cycles). [ABSTRACT FROM AUTHOR]

As a novel electrocatalyst for oxygen reduction reaction (ORR), nitrogen-doped graphene aerogel supported cobalt nanoparticles (Co-NGA) is archived by a hybrid-assembly of graphene oxide (GO), o-phthalonitrile and cobalt acetate and the following thermal treatment. The hybrid-assembly process successfully combines the ionic assembly of GO sheets and Co ions with the coordination between o-phthalonitrile and Co ions, which can be converted to nitrogen doped carbon and Co nanoparticles in the pyrolysis process under nitrogen flow. Remarkable features of Co-NGA including the macroporous graphene scaffolds, high surface area, and N/Co-doping effect can lead to a high catalytic efficiency for ORR. As the results, the composites pyrolyzed at 600 °C (Co-NGA 600 ) shows excellent electrocatalytic activities and kinetics for ORR in basic media, which are comparable with those of Pt/C catalyst, together with superior durability. [ABSTRACT FROM AUTHOR]

Abstract: The development of metal-free catalyst for oxygen reduction reaction (ORR) is one of the most challenging tasks in fuel cells. Heteroatom doped graphenes have been recognized as the promising candidate. In this work, we have developed a one-pot hydrothermal approach towards three-dimensional nitrogen and sulfur co-doped graphene frameworks (N/S-GFs) employing graphene oxide and ammonium thiocyanate as the precursors. N/S-GFs manifest excellent catalytic behavior with mainly four electron transfer pathway in ORR in alkaline condition. [Copyright &y& Elsevier]