Genqiang Zhang

General solution growth of mesoporous NiCo2O4 nanosheets on various conductive substrates as high-performance electrodes for supercapacitors.

Mesoporous NiCo(2) O(4) nanosheets can be directly grown on various conductive substrates, such as Ni foam, Ti foil, stainless-steel foil and flexible graphite paper, through a general template-free solution method combined with a simple post annealing treatment. As a highly integrated binder- and conductive-agent-free electrode for supercapacitors, the mesoporous NiCo(2) O(4) nanosheets supported on Ni foam deliver ultrahigh capacitance and excellent high-rate cycling stability.

Formation of ZnMn2O4 Ball‐in‐Ball Hollow Microspheres as a High‐Performance Anode for Lithium‐Ion Batteries

Novel ZnMn(2)O(4) ball-in-ball hollow microspheres are fabricated by a facile two-step method involving the solution synthesis of ZnMn-glycolate hollow microspheres and subsequent thermal annealing in air. When evaluated as an anode material for lithium-ion batteries, these ZnMn(2)O(4) ball-in-ball hollow microspheres show significantly enhanced electrochemical performance with high capacity, excellent cycling stability and good rate capability.

Hierarchical Tubular Structures Constructed by Carbon‐Coated SnO2 Nanoplates for Highly Reversible Lithium Storage

Hierarchical tubular structures constructed by ultrathin carbon-coated SnO(2) nanoplates are rationally designed and synthesized. This interesting structure simultaneously integrates the structural and compositional design rationales for high-energy anode materials based on low-dimensional ultrathin nanoplates, a hollow tubular structure, and a carbon nanocoating. When evaluated as an anode material for lithium-ion batteries, the as-synthesized SnO(2)-carbon hybrid structure manifests high specific capacity and excellent cycling stability.

Controlled synthesis of hierarchical CoxMn3−xO4 array micro-/nanostructures with tunable morphology and composition as integrated electrodes for lithium-ion batteries

Hierarchical CoxMn3−xO4 array micro-/nanostructures with tunable morphology and composition have been grown on conductive stainless steel with robust adhesion by a facile solvothermal route and a subsequent annealing treatment. By simply controlling the volume ratio of components in the mixed solvent, the morphology of the products can be tailored from hierarchical nanowires to nanosheets. Benefitting from the unique structural features, the resultant CoMn2O4nanowires and MnCo2O4nanosheets exhibit excellent electrochemical performance with remarkable specific capacities (540–207 mA h g−1) at various current rates (1–10 C) and good cycling stability for highly reversible lithium storage. The enhanced electrochemical performance suggests their promising use as integrated binder-free electrodes for microscale lithium-ion batteries.

Strongly Coupled NiCo2O4‐rGO Hybrid Nanosheets as a Methanol‐Tolerant Electrocatalyst for the Oxygen Reduction Reaction

Strongly coupled NiCo2 O4 -rGO hybrid nanosheets are syntheiszed through a cost-effective two-step strategy involving a facile polyol process and subsequent thermal annealing treatment in air. The hybrid nanosheets exhibit impressive electrocatalytic performance for the oxygen reduction reaction (ORR) with a current density and onset potential comparable to those of commercial Pt/C catalyts, while having perfect tolerance to methanol..

TiO2 Hollow Spheres Composed of Highly Crystalline Nanocrystals Exhibit Superior Lithium Storage Properties

While the synthesis of TiO2 hollow structures is well-established, in most cases it is particularly difficult to control the crystallization of TiO2 in solution or by calcination. As a result, TiO2 hollow structures do not really exhibit enhanced lithium storage properties. Herein, we report a simple and cost-effective template-assisted method to synthesize anatase TiO2 hollow spheres composed of highly crystalline nanocrystals, in which carbonaceous (C) spheres are chosen as the removable template. The release of gaseous species from the combustion of C spheres may inhibit the growth of TiO2 crystallites so that instead small TiO2 nanocrystals are generated. The small size and high crystallinity of primary TiO2 nanoparticles and the high structural integrity of the hollow spheres gives rise to significant improvements in the cycling stability and rate performance of the TiO2 hollow spheres.

Rational synthesis of ultrathin n-type Bi2Te3 nanowires with enhanced thermoelectric properties.

A rational yet scalable solution phase method has been established, for the first time, to obtain n-type Bi(2)Te(3) ultrathin nanowires with an average diameter of 8 nm in high yield (up to 93%). Thermoelectric properties of bulk pellets fabricated by compressing the nanowire powder through spark plasma sintering have been investigated. Compared to the current commercial n-type Bi(2)Te(3)-based bulk materials, our nanowire devices exhibit an enhanced ZT of 0.96 peaked at 380 K due to a significant reduction of thermal conductivity derived from phonon scattering at the nanoscale interfaces in the bulk pellets, which corresponds to a 13% enhancement compared to that of the best n-type commercial Bi(2)Te(2.7)Se(0.3) single crystals (~0.85) and is comparable to the best reported result of n-type Bi(2)Te(2.7)Se(0.3) sample (ZT = 1.04) fabricated by the hot pressing of ball-milled powder. The uniformity and high yield of the nanowires provide a promising route to make significant contributions to the manufacture of nanotechnology-based thermoelectric power generation and solid-state cooling devices with superior performance in a reliable and a reproducible way.

General Formation of Complex Tubular Nanostructures of Metal Oxides for the Oxygen Reduction Reaction and Lithium‐Ion Batteries

General Formation of Complex Tubular Nanostructures of Metal Oxides for the Oxygen Reduction Reaction and LithiumIon Batteries Tube in a tube : A general strategy for the fabrication of novel complex tube-in-tube nanostructures for many metal oxides has been developed. The method involves coating carbon nanofibers with a layer of metal glycolate followed by calcination in air. The unique complex tubular structures of metal oxides are shown to exhibit promising properties for the title applications. Angewandte Chemie

Nontoxic and Abundant Copper Zinc Tin Sulfide Nanocrystals for Potential High-Temperature Thermoelectric Energy Harvesting

Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance.

Strongly coupled carbon nanofiber–metal oxide coaxial nanocables with enhanced lithium storage properties

A facile two-step strategy involving a polyol method and subsequent thermal annealing treatment is successfully developed for the general synthesis of metal oxide/carbon coaxial nanocables. Benefitting from the strong coupling effect, these hybrid nanocables exhibit remarkable lithium storage properties with high capacity, long cycle life and excellent rate capability.