Single crystalline Bi2S3 nanorods have been synthesized by a tartaric acid-assisted hydrothermal route. The presence of tartaric acid is found to be essential for one-dimensional growth of the ...product. X-ray diffraction (XRD) pattern identified the product to be of orthorhombic phase and growth direction of the nanorods along the specific plane has been determined through a series of high-resolution electron microscopy (HREM) studies that agrees well with the general direction of growth for one-dimensional (1D) nanomaterials. These nanorods have been subsequently coated with polypyrrole (PPy) for the first time in order to prepare a material with hybrid core−shell structure. The coating obtained is smooth in nature and uniform in thickness. The shell thickness could be changed by controlling the monomer concentration and varies linearly with monomer input. Raman spectra have been also used to characterize the PPy-coated nanorods.
CuS nanorods of length 60–100 nm and 15 nm in diameter have been synthesized by simple wet chemical method at 105 °C using CuCl
2·2H
2O as Cu-precursor, CS
2 as S-source and ethylenediamine as the ...attacking reagent. The plausible reaction mechanism has been proposed and the effect of reaction temperature on morphology has been discussed. X-ray diffraction (XRD) pattern suggests the formation of hexagonal phase CuS. The morphology of the products has been studied by transmission electron microscope (TEM) analysis. A detailed optical study has also been done.
ZnS thin films have been deposited by chemical bath deposition method using tartaric acid as a complexing agent. The structural and morphological characteristics of films have been investigated by ...X-ray diffraction (XRD), scanning electron microscope and atomic force microscope analysis. XRD shows development of well-crystallized film with pure-wurtzite structure after annealing. The films show good optical properties with high transmittance in the visible region and the band gap value was estimated to be 3.69 eV. The photoluminescence spectrum of films has also been studied.
Graphene nanocomposites of CdS and ZnS in effective water purification Sahoo, Ashish Kumar; Srivastava, Suneel Kumar; Raul, Prasanta Kumar ...
Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology,
07/2014, Letnik:
16, Številka:
7
Journal Article
The present work deals with syntheses of CdS/graphene and ZnS/graphene nanocomposites by hydrothermal reaction of graphene oxide and morpholine-4-carbodithioate complex of Cd and Zn, respectively. ...The corresponding nanocomposites has been investigated separately as photocatalyst in the decomposition of methylene blue in the presence of UV light and also as adsorbents in the removal of Cd(II) and Pb(II) ions in contaminated water. These studies have established that CdS/graphene and ZnS/graphene are effective photocatalyst as well as effective adsorbents in the removal of Cd(II) and Pb(II) ions to an extent of 97 and 99 % by ZnS/graphene and CdS/graphene nanocomposite, respectively, under 1 g L
−1
of adsorption dose and at pH ~7. Further studies also established Langmuir model befitting for the adsorption of Pb(II) and Cd(II) ions on CdS/graphene and ZnS/graphene, respectively. The presence of interfering ions on extent of Cd(II) and Pb(II) removal has also been reported.
The present work reports on the fabrication of a lightweight microwave absorber comprising MnCo2O4 prepared from the urea complex of manganese (Mn)/cobalt (Co) and nitrogen-doped reduced graphite ...oxide (NRGO) by facile hydrothermal method followed by annealing process and characterized. The phase analysis, compositional, morphological, magnetic, and conductivity measurements indicated dispersion of paramagnetic MnCo2O4 spherical particles on the surface of NRGO. Our findings also showed that Mn, Co–urea complex, and GO in the weight ratio of 1:4 (NGMC3) exhibited maximum shielding efficiency in the range of 55–38 dB with absorption as an overall dominant shielding mechanism. The reflection loss of NGMC3 was found to be in the range of −90 to −77 dB with minima at −103 dB (at 2.9 GHz). Such outstanding electromagnetic wave absorption performance of NRGO/MnCo2O4 nanocomposite compared to several other metal cobaltates could be attributed to the formation of percolated network assisted electronic polarization, interfacial polarization and associated relaxation losses, conductance loss, dipole polarization and corresponding relaxation loss, impedance matching, and magnetic resonance to some extent.
Silicone rubber (SR)/Mg-Al layered double hydroxide (LDH) nanocomposites were prepared by the solution intercalation of SR crosslinked by a platinum-catalyzed hydrosilylation reaction into the ...galleries of dodecyl sulfate intercalated layered double hydroxide (DS-LDH). X-ray diffraction and transmission electron microscopy analysis showed the formation of exfoliated structures of organomodified LDH layers in the SR matrix. The tensile strength and elongation at break of SR/DS-LDH (5 wt %) were maximally improved by 53 and 38%, respectively, in comparison with those of the neat polymer. Thermogravimetric analysis indicated that the thermal degradation temperature of the exfoliated SR/DS-LDH (1 wt %) nanocomposites at 50% weight loss was 20°C higher than that of pure SR. Differential scanning calorimetry analysis data confirmed that the melting temperature of the nanocomposites increased at lower filler loadings (1, 3, and 5 wt %), whereas it decreased at a higher filler loading (8 wt %). The relative improvements in the solvent-uptake resistance behavior of the SR/DS-LDH nanocomposites were also observed.
The present work highlights fabrication of nanostructured nickel-substituted cobalt carbonate hydroxide hydrates (NCCHH) through one-step reflux method. It is noted that optimized 30 mol% ...nickel-substituted cobalt carbonate hydroxide hydrate (NCCHH-30) nanostructures show quite high specific surface area (∼229.55 m2 g−1) owing to the formation of hierarchically hollow interconnected ring-type morphology facilitating the electrode-electrolyte interfacial interaction. As a result, NCCHH-30 showed significant amplification in electrocatalytic oxygen evolution reaction (OER) activity with ultralow overpotential (∼141 mV @ 10 mA cm−2), Tafel slope (∼49 mV dec−1), and excellent durability (12 h and 2000 cycles) in 1.0 M KOH. Notably, to the best of our knowledge, interconnected NCCHH-30 hierarchical hollow rings exhibited the best overpotential (η100 ∼198 mV) value reported for cobalt-based electrocatalysts in alkaline OER. In addition, this material exhibited exceptionally high oxygen evolution performance in comparison to the state-of-the-art commercial RuO2 electrocatalyst in 1.0 M KOH. Such interconnected hierarchically hollow nickel (30 mol%)-substituted cobalt carbonate hydroxide hydrate nanostructured rings could act as an ultraefficient, cost-effective, and stable electrocatalyst for OER in alkaline medium.
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•Fabrication of Ni-substituted cobalt carbonate hydroxide hydrate (NCCHH-30) interconnected hierarchically hollow rings.•The NCCHH-30 shows ultralow OER overpotential of ∼141 mV at 10 mA cm−2 in 1.0 KOH.•The NCCHH-30 demonstrates more than two times lower alkaline OER overpotential than the commercial RuO2.
Molybdenum disulfide (MoS(2))-multiwalled carbon nanotube (MWCNT) hybrids have been prepared by simple dry grinding. Excellent initial charge capacity (1214 mA h g(-1)) and ~85% retention after 60 ...discharge-charge cycles at different current densities (100-500 mA g(-1)) make MoS(2)-MWCNT (1 : 1) hybrids a superior anode in Li-ion batteries.
The present work is focused on the synthesis of bismuth sulfide (Bi2S3) nanorod/reduced graphene oxide (RGO) composites via a one-step hydrothermal method using GO and bismuth nitrate in 5 : 1, 3 : 1 ...and 2 : 1 weight ratios and their characterization. The morphological studies revealed the formation of homogeneously dispersed Bi2S3 nanorods on RGO sheets along with occasional wrapping in the Bi2S3 nanorod/RGO (3 : 1) composite. XRD, FTIR, Raman and XPS studies suggested the incorporation of Bi2S3 in RGO sheets. The galvanostatic charge–discharge measurements showed that the Bi2S3 nanorod/RGO (3 : 1) composite exhibited the highest specific capacitance (1932 F g−1) at 1 A g−1 in the presence of 2 M aqueous KOH in a three-electrode cell. This is ascribed to the enhanced contact area between metal sulfide nanoparticles and RGO, increased conductivity and synergistic effect of Bi2S3 and RGO. The optimized Bi2S3 nanorod/RGO (3 : 1) composite also maintained an excellent cycling stability with ∼100% capacitance retention after 700 cycles. It is noted that the supercapacitor performance of the Bi2S3 nanorod/RGO (3 : 1) composite was better than group V and VI metal chalcogenides and their nanocomposites reported in several previous studies.
