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Magnetic carbon nanostructures from microwave assisted- and conventional-pyrolysis processes are compared. Unlike graphitized carbon shells from conventional heating, different carbon shell morphologies including nanotubes, nanoflakes and amorphous carbon were observed. Crystalline iron and cementite were observed in the magnetic core, different from a single cementite phase from the conventional process.

Herein a facile hydrothermal approach is used to construct carbon coated TiO2 nanoparticles employing dextrose as the source of carbon. The procedure is operated at a low temperature of 200 °C. Fourier infrared spectroscopy demonstrated the successful coating of carbon on TiO2 nanoparticles. The phase composition of TiO2 and carbon coated TiO2 nanoparticles were studied using X-ray diffraction and the surface morphology was analyzed by scanning and transmission electron microscopy. The existence of carbon coating on TiO2 nanoparticles was revealed by thermogravimetric analysis through different thermograms exhibited for TiO2 and carbon coated TiO2 nanoparticles. The reported method offers a simple and efficient approach for production of carbon coated TiO2 nanoparticles., (Published by Elsevier B.V.)

Abstract: Novel mesoporous carbon has been synthesized using rod-like nano-hydroxyapatite (HA) particles as templates, sucrose as carbon precursor by polymerizing, carbonizing and the removal of templates with HCl solution. In the process, HA not only acted as an endotemplate but also an exotemplate producing micropores and mesopores. Subsequently, mesoporous carbon was modified by HNO3 solution with different concentration. The morphology, pore structure, and surface functional groups of the as-obtained samples are analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller method (BET), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The electrochemical performance for electrochemical capacitors is evaluated in a 1M H2SO4 aqueous solution. The results manifest that the structrue of resultant carbon with a high surface area (719.7m2 g−1) and large pore volume (1.51cm3 g−1) is the replica of HA. After modification, the surface area and pore volume mesoporous carbons slightly decrease, while their electrochemical performance have been significantly improved with the increase of the capacitance from 125.7 to 170.1Fg−1 and a non-decayed cycle life over 5000 cycles for HA-C-0.15N. [Copyright &y& Elsevier]

Abstract Both magnetic transition and magnetocaloric properties of LaFe 11.6 Si 1.4 doped with boron (B) and carbon (C) were investigated. Experimental data showed that nearly pure τ 1 phase was obtained in LaFe 11.6 Si 1.4 , LaFe 11.6 Si 1.4 B 0.06 and LaFe 11.6 Si 1.4 C 0.06 alloys after annealing at 1373 K for 100 h. All annealed samples underwent a first-order magnetic transition. B doping decreased the magnetic transition temperature from 192 K to 188 K, whereas C doping increased to 206 K. In combination with X-ray diffraction results, the density-functional theory was used to reconstruct the unit-cell in order to understand the magnetic transition behavior. The results suggested that almost all B atoms occupy 96 i FeII/Si substitutional site, and all C atoms prefer 24 d interstitial site in the present given conditions. The annealed samples possessed the maximum magnetic entropy changes higher than 20 J/(kg⋅K) under a magnetic field change of 3 T, and their effective refrigeration capacities reached 200 J/kg. Highlights • Doping effects of boron and carbon on La−Fe−Si compounds were investigated. • Density-functional theory was used to reconstruct the crystallographic unit-cell. • The occupation information of boron and carbon in La−Fe−Si was clarified. [ABSTRACT FROM AUTHOR]

Abstract: Herein a facile hydrothermal approach is used to construct carbon coated TiO2 nanoparticles employing dextrose as the source of carbon. The procedure is operated at a low temperature of 200°C. Fourier infrared spectroscopy demonstrated the successful coating of carbon on TiO2 nanoparticles. The phase composition of TiO2 and carbon coated TiO2 nanoparticles were studied using X-ray diffraction and the surface morphology was analyzed by scanning and transmission electron microscopy. The existence of carbon coating on TiO2 nanoparticles was revealed by thermogravimetric analysis through different thermograms exhibited for TiO2 and carbon coated TiO2 nanoparticles. The reported method offers a simple and efficient approach for production of carbon coated TiO2 nanoparticles. [Copyright &y& Elsevier]