Huaqiang Cao

ZnO@graphene composite with enhanced performance for the removal of dye from water

A ZnO@graphene composite exhibits enhanced performance for photocatalytic degradation and filtered removal of RhB dye, in comparison with ZnO and graphene, highlighting its potential applications for a variety of environmental issues.

Co3O4@graphene Composites as Anode Materials for High-Performance Lithium Ion Batteries

This paper reports on the synthesis of Co(3)O(4)@graphene composites (CGC) and their applications as anode materials in lithium ion batteries (LIBs). Through a chemical deposition method, Co(3)O(4) nanoparticles (NPs) with sizes in the range of 10-30 nm were homogeneously dispersed onto graphene sheets. Due to their high electrical conductivity, the graphene sheets in the CGC improved the electrical conductivity and the structure stability of CGC. CGC displayed a superior performance in LIBs with a large reversible capacity value of 941 mA hg(-1) in the initial cycle with a large current density and an excellent cyclic performance of 740 mA hg(-1) after 60 cycles, corresponding to 88.3% of the theoretical value of CGC, owing to the interactions between graphene sheets and Co(3)O(4) NPs anchored on the graphene sheets. This synthesis approach may find its application in the design and synthesis of novel electrode materials used in LIBs.

Superparamagnetic Fe3O4 nanocrystals@graphene composites for energy storage devices

In this paper, a Fe3O4 nanocrystals@graphene composite (FGC) was synthesized via a chemical deposition method by using graphene oxide as a precursor. We also investigate the structures, physicochemical properties and applications of FGCs, involving superparamagnetic performance, and use as supercapacitors and lithium ion battery (LIBs). The results showed that the Fe3O4 NCs were formed and incorporated onto the surface of the graphene sheets. The composite material FGC with a micrometre scale structure possessed similar size as the graphene sheets and exhibited superparamagnetic behavior at room temperature. The supercapacitance values of the FGC composites were enlarged compared with those of the graphene sheets or Fe3O4 NCs, which is attributed to the interaction between the Fe3O4 NCs and the graphene sheets. Meanwhile, a superior rechargeable stability of FGCs used as an anode material in LIBs can be observed.

Enhanced anode performances of the Fe3O4–Carbon–rGO three dimensional composite in lithium ion batteries

A three dimensional composite was constructed by anchoring Fe(3)O(4) nanoparticles encapsulated within carbon shells onto reduced graphene oxide sheets, which exhibited enhanced anode performances in lithium ion batteries with a specific capacity of 842.7 mAh g(-1) and superior recycle stability after 100 cycles.

Cu2O@reduced graphene oxide composite for removal of contaminants from water and supercapacitors

Cu2O@reduced graphene oxide composite displays a good ability to remove dyes from water and high stability in supercapacitors, highlighting potential applications in environmental and energy storage issues.

Room-temperature ultraviolet-emitting In2O3 nanowires

Semiconductor In2O3 nanowires embedded in an alumina template were fabricated using template technology. Scanning electron microscopy and transmission electron microscopy observations show that the In2O3 nanowire single crystal has an average diameter around 80 nm and a length over 10 μm. A strong photoluminescence (PL) emission with a peak at 398 nm (3.12 eV in photon energy) was detected upon excitation of the In2O3 nanowires at 274 nm (4.53 eV in photon energy) and 305 nm (4.08 eV in photon energy) under room temperature. The observed UV PL emission is attributed to the near band edge emission.

Synthesis and superior anode performance of TiO2@reduced graphene oxide nanocomposites for lithium ion batteries

Herein, we report the synthesis of TiO2-reduced graphene oxide composite (termed as TGC) nanostructures using tetrabutyl titanate as the titanium source via a solvothermal route. The TGC nanostructures were characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and adsorption–desorption isotherms for nitrogen measurements. The TGC was used as the anode of lithium ion batteries for investigation. The hybrid nanocomposite exhibited remarkable improvement in lithium ion insertion/extraction behaviour compared with TiO2, which showed an initial irreversible capacity and a reversible capacity of 386.4 and 152.6 mAh g−1 for TGC after 100 cycles at a high charge rate of 5 C (1000 mA g−1), compared to 69.5 and 9.7 mAh g−1 for TiO2, respectively. The enhanced electrochemical performance of TGC is attributed to the increased conductivity in the presence of reduced graphene oxide in TGC, the small size of the TiO2 particles in TGC, which can shorten the transport paths for both Li+ ions and electrons, and the enlarged electrode–electrolyte contact area, leading to more electroactive sites in TGC.

Biomolecule-assisted synthesis of water-soluble silver nanoparticles and their biomedical applications.

The application of nanoparticles in the biomedical field is an exciting interdisciplinary research area in current materials science. In the present study, size-tunable and water-soluble noble metal silver nanoparticles (Ag NPs) have been successfully synthesized with the assistance of glutathione (GSH). The as-synthesized Ag NPs are ready to bind covalently with a model protein (bovine serum albumin) in mild conditions. The optical property of surface-modifiable Ag NPs was extremely sensitive to their size and the surface modification, suggesting a potential in the biomedical analysis and detection. Furthermore, Ag NPs with an average diameter of ca. 6 nm effectively suppress the proliferation of human leukemic K562 cells in the dose- and time-dependent manners, suggesting the promising potential of Ag NPs in cancer therapy.

Mg(OH)2@reduced graphene oxide composite for removal of dyes from water

The Mg(OH)2@reduced graphene oxide (rGO) composite (MGC) was synthesized via a chemical deposition method. Its mesoporous structures and application as an adsorbent for the removal of methylene blue (MB) from water were investigated. The Mg(OH)2 nanosheets were formed and dispersed homogeneously onto the surface of rGO sheets, which provided high surface area, pore volume, and uniform pore width distribution. MGC exhibited excellent adsorption behavior for MB.

Designed synthesis of SnO2-polyaniline-reduced graphene oxide nanocomposites as an anode material for lithium-ion batteries

Three dimensional SnO2-based nanocomposites, i.e., SnO2 nanoparticles anchored on polyaniline nanoplates@reduced graphene oxide nanosheets (SPG) viaπ–π stacking, present excellent cyclability and high capacity with a reversible storage capacity of 573.6 mA h g−1 accompanied by coulombic efficiency of 99.26% over 50 cycles when used as an anode in a lithium ion battery.