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Adsorption of Ni2+ from aqueous solution by magnetic Fe@graphite nano-composite

Konicki W., Pelka R., Arabczyk W.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 4

96--103

EN

The removal of Ni2+ from aqueous solution by iron nanoparticles encapsulated by graphitic layers (Fe@G) was investigated. Nanoparticles Fe@G were prepared by chemical vapor deposition CVD process using methane as a carbon source and nanocrystalline iron. The properties of Fe@G were characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform-Infrared Spectroscopy (FTIR), BET surface area and zeta potential measurements. The effects of initial Ni2+ concentration (1–20 mg L−1 ), pH (4–11) and temperature (20–60°C) on adsorption capacity were studied. The adsorption capacity at equilibrium increased from 2.96 to 8.78 mg g−1 , with the increase in the initial concentration of Ni2+ from 1 to 20 mg L−1 at pH 7.0 and 20°C. The experimental results indicated that the maximum Ni2+ removal could be attained at a solution pH of 8.2 and the adsorption capacity obtained was 9.33 mg g−1 . The experimental data fitted well with the Langmuir model with a monolayer adsorption capacity of 9.20 mg g−1 . The adsorption kinetics was found to follow pseudo-second-order kinetic model. Thermodynamics parameters, ΔHO, ΔGO and ΔSO, were calculated, indicating that the adsorption of Ni2+ onto Fe@G was spontaneous and endothermic in nature.

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Preparation and photocatalytic activity of iron- modified titanium dioxide photocatalyst

Lezner M., Grabowska E., Zaleska A.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 1

193-200

EN

Iron modified TiO2 was prepared by the sol-gel method and surface modification method followed by calcination at 400°C. Two types of titanium dioxide: TiO2 ST-01(Ishihara Sangyo Ltd., Japan;300 m2/g), and TiO2 P25 (Evonik, Germany, 50 m2/g) were used in the grinding procedure. The photocatalysts were characterized by UV-VIS absorption and BET surface area measurements. The photocatalytic activity of the obtained powders in UV-Vis and visible light was estimated by measuring the decomposition rate of phenol (0.21 mmol/dm3) in an aqueous solution. The best photoactivity under visible light was observed for iron doped TiO2 with 0.5% by grinding the TiO2 ST-01.

3

Formation of Nano-pillar Iron Catalyst Nucleating he Multi-walled Carbon Nanotube Growth

Stobiński L., Tomasik P.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 11

1971-1981

EN

The nano-form of iron catalyst for the carbon nanotubes (CNTs) growth was prepared in a separate process. First, a thin iron layer was thermally deposited under a high vac uum onto the sur face of the SiO2/Si sub strate at about 300 K. That cat a lyst sur face was treated with hydrogen at 700°C, followed by a subsequent heating at 750°C in the pure ethylene at mosphere. After the hydrogen treatment a continuous, smooth Fe layer was turned into a set of well separated Fe nano-pillars. Deposited multi-walled CNTs (MWCNTs) were examined with atomic force (AFM), scanning electron (SEM) and high resolution trans - mission electron (HR-TEM) microscopic techniques. Applied pretreatment of the catalyst with hydrogen and chemical vapour deposition of MWCNTs from pure ethylene al lowed to propose the growth mechanism for long, straight and catalyst free MWCNTs. It seems that this kind of CNTs structure is the most serious candidate in a future nano-electronic. The results suggest a certain control of the diameter of CNTs.