A Simple Hydrothermal Synthesis of Cadmium Sulfide Wrapped on Graphene Nanocomposite for Supercapacitor Applications.

Supercapacitor with high specific capacity is desirable for various energy storage and high powerdensity applications. Though Graphene has been the preferred material for high current density, nanocomposites have been attempted to increase the specific capacitance. Hydrothermal synthesis of cadmium sulfide/graphene (CdS/G) nanocomposite with CdS nanoparticles anchored/decorated over the graphene sheets is reported. The structural studies reveal the hexagonal phase of the prepared materials. The specific surface area (BET) and porosity is found to increase upon nanocomposite formation. The electrochemical characteristics such as cyclic voltammetry (CV), GCD and EIS of the CdS/G nanocomposite have been investigated. The capacitance of CdS/G nanocomposite almost doubled to 248 Fg-1 indicating the enhanced performance of the nanocomposite system and in addition it also showed excellent cycling stability of 74.8 percent after 1000 cycles. The supercapacitor investigated retained the initial energy density after charge-discharge, at 0.5 A/g for 1000 cycles. The graphene nanosheets increased the specific surface area and interfacial electron transfer of the composite material. It enhances the specific capacitance and cyclic stability of the supercapacitor device.

A Cost Effective, Facile Hydrothermal Approach of Zinc Sulfide Decorated on Graphene Nanocomposite for Supercapacitor Applications.

A cost effective, facile hydrothermal method was used for the synthesis of ZnS/graphene (G) nano-composites. The XRD analysis clearly confirmed the presence of cubic sphalerite structure of ZnS which maintained its structure both in pure and composite materials matrix. The spectroscopic investigations like FTIR and FT-Raman analysis, and optical studies of the ZnS and ZnS/G nanocomposite were also carried out. The thermal behaviour of ZnS and ZnS/G nanocomposite showed that ZnS/G have higher thermal stability. The SEM analysis showed the spherical nature of ZnS nanoparticles covered over the surface of the graphene sheets and elemental composition of the GO, ZnS and ZnS/G nanocomposite was analyzed by EDAX analysis. The electrochemical properties of the prepared nanocomposite were investigated using cyclic voltammetry and galvanostatic charge discharge techniques. The specific capacitance of ZnS and ZnS/G nanocomposite was found to be 129.67, 315.1, respectively, at 5 mV/s scan rate. The obtained results are compared with reported results and the results indicate the possibility that, the synthesized sample have a good potential to be used as an electrode materials for high energy super capacitor applications.

Tailoring the surface-oxygen defects of a tin dioxide support towards an enhanced electrocatalytic performance of platinum nanoparticles.

Tin-dioxide nanofacets (SnO2 NFs) are crystal-engineered so that oxygen defects on the maximal {113} surface are long-range ordered to give rise to a non-occupied defect band (DB) in the bandgap. SnO2 NFs-supported platinum-nanoparticles exhibit an enhanced ethanol-electrooxidation activity due to the promoted charge-transport via the DB at the metal-semiconductor interface.

Low-temperature remediation of NO catalyzed by interleaved CuO nanoplates.

A copper(II)-oxide-based exhaust catalyst exhibits better activity than Pt- and Rh-nanoparticle catalysts in NO remediation at 175 °C. Following theoretical design, the CuO catalyst is rationally prepared; CuO nanoplates bearing a maximized amount of the active {001} facet are arranged in interleaved layers. A field test using a commercial gasoline engine demonstrates the ability of the catalyst to remove NO from the exhaust of small vehicles.

Interleaved mesoporous copper for the anode catalysis in direct ammonium borane fuel cells.

Mesoporous materials with tailored microstructures are of increasing importance in practical applications particularly for energy generation and/or storage. Here we report a mesoporous copper material (MS-Cu) can be prepared in a hierarchical microstructure and exhibit high catalytic performance for the half-cell reaction of direct ammonium borane (NH3BH3) fuel cells (DABFs). Hierarchical copper oxide (CuO) nanoplates (CuO Npls) were first synthesized in a hydrothermal condition. CuO Npls were then reduced at room temperature using water solution of sodium borohydride (NaBH4) to yield the desired mesoporous copper material, MS-Cu, consisting of interleaved nanoplates with a high density of mesopores. The surface of MS-Cu comprised high-index facets, whereas a macroporous copper material (MC-Cu), which was prepared from CuO Npls at elevated temperatures in a hydrogen stream, was surrounded by low-index facets with a low density of active sites. MS-Cu exhibited a lower onset potential and improved durability for the electro-oxidation of NH3BH3 than MC-Cu or copper particles because of the catalytically active mesopores on the interleaved nanoplates.

Photocatalytic water splitting under visible light by mixed-valence Sn(3)O(4).

A mixed-valence tin oxide, (Sn(2+))2(Sn(4+))O4, was synthesized via a hydrothermal route. The Sn3O4 material consisted of highly crystalline {110} flexes. The Sn3O4 material, when pure platinum (Pt) was used as a co-catalyst, significantly catalyzed water-splitting in aqueous solution under illumination of visible light (λ > 400 nm), whereas neither Sn(2+)O nor Sn(4+)O2 was active toward the reaction. Theoretical calculations have demonstrated that the co-existence of Sn(2+) and Sn(4+) in Sn3O4 leads to a desirable band structure for photocatalytic hydrogen evolution from water solution. Sn3O4 has great potential as an abundant, cheap, and environmentally benign solar-energy conversion catalyst.