•Novel hybrid of MnSnO3 and nitrogen-doped reduced graphene oxide was fabricated.•The MnSnO3 nanoparticles possess amorphous and hollow structure in the composite.•The excellent electrochemical performance benefits from unique nanostructure.•The reversible capacity of as-prepared hybrid is 610 mAh g−1 after 1000 cycles.•A long-term life with 97.3% capacity retention over 1000 cycles was obtained.Tin-based metal oxides usually suffer from severe capacity fading resulting from aggregation and considerable volume variation during the charge/discharge process in lithium ion batteries. In this work, a novel nanocomposite (MTO/N-RGO) of hollow amorphous MnSnO3 (MTO) nanoparticles and nitrogen-doped reduced graphene oxide (N-RGO) has been designed and synthesized by a two-step method. Firstly, the nitrogen-doped graphene nanocomposite (MTO/N-RGO-P) with MnSn(OH)6 crystal nanoparticles was synthesized by a facile solvothermal method. Subsequently, the MTO/N-RGO nanocomposite was obtained through the post heat treatment of MTO/N-RGO-P. The designed heterostructure and well-combination of the hollow amorphous MTO and N-RGO matrix can accelerate the ionic and electronic transport, and simultaneously accommodate the aggregation and volume variation of MTO nanoparticles during the lithiation–delithiation cycles. The as-prepared hybrid of MTO and N-RGO (MTO/N-RGO) exhibits a high reversible capacity of 707 mAh g−1 after 110 cycles at 200 mA g−1, superior rate capability, and long-term cyclic life with high capacity of 610 mAh g−1 over 1000 cycles at 400 mA g−1. Superior capacity retention of 97.3% over 1000 cycles was obtained. This work opens new opportunities to fabricate the high-performance electrode materials with heterostructure for lithium storage systems, especially for novel multi-metal oxide based nanocomposites with high cycling stability.A novel hybrid of hollow amorphous MnSnO3 nanoparticles and nitrogen-doped reduced graphene oxide was fabricated. The unique structure and well-combination of both components account for the ultra long-term cyclic life with high reversible capacity of 610 mAh g−1 over 1000 cycles at 400 mA g−1.

The physicochemical property of chemically prepared graphene can be significantly changed due to the incorporating of heteroatoms into graphene. In this article, boron-doped graphene sheets are used as carbon substrates instead of graphene for loading polyaniline by in situ polymerization. Compared with the individual component and polyaniline/non-doped graphene, the sandwich-like polyaniline/boron-doped graphene exhibits remarkably enhanced electrochemical specific capacitance in both acid and alkaline electrolytes. In a three-electrode configuration, the hybrid has a specific capacitance about 406 F g−1 in 1 M H2SO4 and 318 F g−1 in 6 M KOH at 1 mV s−1. In the two-electrode system of a symmetric supercapacitor, this hybrid achieves a specific capacitance about 241 and 189 F g−1 at 0.5 A g−1 with a specific energy density around 19.9 and 30.1 Wh kg−1, in the acid and alkaline electrolytes, respectively. The as-obtained polyaniline/boron-doped graphene hybrid shows good rate performance. Notably, the obtained electrode materials exhibit long cycle stability in both acid and alkaline electrolytes (∼100% and 83% after 5000 cycles, respectively). The improved electrochemical performance of the hybrid is mainly attributed to the introduction of additional p-type carriers in carbon systems by boron-doping and the well combination of pseudocapacitive conducting polyaniline.

The controllable synthesis of 3D inorganic nanomaterials has attracted much attention. Here, 3D hierarchical mesoporous cobalt oxide (Co3O4) nanomaterials with different morphologies are successfully prepared by a facile and surfactant-free solvothermal synthesis of cobalt carbonate hydroxide and subsequent calcination. The morphology of the precursor can be well controlled by adjusting the experimental conditions, such as the proportion of solvent, the amount of urea, and reaction time, thus controlling the structures of the cobalt oxide. Two different plausible growth mechanisms of the red-headed calliandra-like and dandelion-flower-like precursors have been investigated by transmission electron spectroscopy (TEM) of the time-dependent products, respectively. The hierarchical mesoporous materials are tested as the anode materials for lithium ion batteries (LIBs). In particular, the hierarchical mesoporous dandelion-flower-like cobalt oxide shows good rate performance and high specific capacities of 1298 mA h g–1 at the first cycle and 1204 mA h g–1 over 20 cycles, whereas those of the red-headed calliandra-like mesoporous Co3O4 are 1340 and 833 mA h g–1, respectively. In addition, the as-prepared mesoporous cobalt oxides are evaluated as the catalyst for the oxygen reduction reaction (ORR).

The large-scale synthesis of ternary nanocomposite hemin–graphene sheets/poly(3,4-ethylenedioxythiophene) (H–GNs/PEDOT) was achieved via a microwave-assisted method, in which PEDOT was polymerized with graphene oxide and induced with hemin on the H–GNs nanosheets without additional oxidants; meanwhile, graphene oxide was partially reduced simultaneously. The morphology and structure of the as-prepared nanocomposites were characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible absorption spectroscopy. The H–GNs/PEDOT nanocomposite combines the main excellent properties of the three components, maintaining the peroxidase-like activity of hemin, and displaying a high-speed electron transfer ascribed to the presence of PEDOT and the graphene sheets. The H–GNs/PEDOT exhibited remarkable electrocatalysis towards the reduction of H2O2 due to the direct electron-transfer between the hemin and the modified electrode. The excellent synergic effect enables an enhanced electrochemical performance of the H–GNs/PEDOT modified electrode with good biocompatibility and fast redox property. The novel biomimetic H2O2 biosensor based on the well-designed ternary hybrid H–GNs/PEDOT has a low detection limit (0.08 μM) with a high dynamic response range (10−7 to 10−5 M) and a high sensitivity (235 μA mM−1 cm−2). The sensor displays good selectivity, repeatability, reproducibility and stability.

A graphene oxide/manganese oxide/polyaniline composite (GOM) was synthesized via a one-step method at room temperature, and its reduced graphene oxide/manganese oxide/polyaniline (RGOM) composites were prepared under different reaction conditions. The relationships between the synthesis approach, structure and electrochemical properties of the manganese oxide ternary composites were systematically investigated. The reaction temperature and the basic concentration played important roles in the reduction process. The possible reaction mechanisms of the ternary composites were proposed. The results show that high temperature under hydrothermal conditions can lead to a higher crystallinity degree, and promote the formation of the fiber-like nanostructure of the composites. Meanwhile, the higher concentration of NaOH promotes the reduction of MnO2 to other manganese oxides with a lower valence. The electrochemical characterization shows that, among those composites, the specific capacity of RGOM5 with a rough and sheathed nanostructure, obtained using 8 M NaOH at 120 °C via a hydrothermal method, can reach 344 F g−1 at a scan rate of 1 mV s−1, and the capacitive retention proportion remains nearly 100% after 6000 cycles, which presents a promising future for RGOM composites acting as low cost energy storage materials.

The large-scale synthesis of ternary nanocomposite hemin–graphene sheets/poly(3,4-ethylenedioxythiophene) (H–GNs/PEDOT) was achieved via a microwave-assisted method, in which PEDOT was polymerized with graphene oxide and induced with hemin on the H–GNs nanosheets without additional oxidants; meanwhile, graphene oxide was partially reduced simultaneously. The morphology and structure of the as-prepared nanocomposites were characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible absorption spectroscopy. The H–GNs/PEDOT nanocomposite combines the main excellent properties of the three components, maintaining the peroxidase-like activity of hemin, and displaying a high-speed electron transfer ascribed to the presence of PEDOT and the graphene sheets. The H–GNs/PEDOT exhibited remarkable electrocatalysis towards the reduction of H2O2 due to the direct electron-transfer between the hemin and the modified electrode. The excellent synergic effect enables an enhanced electrochemical performance of the H–GNs/PEDOT modified electrode with good biocompatibility and fast redox property. The novel biomimetic H2O2 biosensor based on the well-designed ternary hybrid H–GNs/PEDOT has a low detection limit (0.08 μM) with a high dynamic response range (10−7 to 10−5 M) and a high sensitivity (235 μA mM−1 cm−2). The sensor displays good selectivity, repeatability, reproducibility and stability.