Research Article
Effect of the Deposition Potential on Morphology, Nucleation, and Crystal Orientation of Nickel Electrodeposited
Koutouan Desire Martial Abro*,
Ali Sanou,
Edith Kouassi i Kwa-Koff
Issue:
Volume 13, Issue 1, April 2024
Pages:
1-8
Received:
15 December 2023
Accepted:
27 December 2023
Published:
8 January 2024
Abstract: The works reported in this paper deal with the effects of the electrodeposition potential on the morphology, the nucleation, and the crystallographic features of the nickel electrodeposited from a Watts-type bath. For this purpose, coatings electrodeposited at five different deposition potentials from –0.60 V/Ag/AgCl to –0.80 V/Ag/AgCl were investigated. The morphology of the coatings was studied using scanning electron microscopy, and the current transients were compared to the 2D and 3D theoretical models of nucleation and growth. Then, the diffractograms were plotted as a function of the deposition potential. The results showed that the coatings are uniform when deposited at –0.60 V/Ag/AgCl. The nucleation and growth of coatings all follow the instantaneous models in the potential window of study but switch from 2D to 3D at –0.65 V/Ag/AgCl. These different features of the coatings have been attributed to the hydrogen evolution reaction which represents up to 10 % of the total current at –0.80 V/Ag/AgCl. Besides, the calculation of the texture coefficient extracted from the X-ray diffraction data has indicated the plane (220) as the preferred crystal orientation. Also, the observation of the shifts of the peaks has demonstrated the presence of uniform stress in the electrocoatings deposited from –0.60 V/Ag/AgCl to –0.75V/Ag/AgCl. Above, tensile stress appears.
Abstract: The works reported in this paper deal with the effects of the electrodeposition potential on the morphology, the nucleation, and the crystallographic features of the nickel electrodeposited from a Watts-type bath. For this purpose, coatings electrodeposited at five different deposition potentials from –0.60 V/Ag/AgCl to –0.80 V/Ag/AgCl were investi...
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Research Article
Synthesis of Activated Carbon from Cassava Peeling and Its Applications for Removal of Methylene Blue
Ouro-Agoro Faouzou,
Dougna Akpénè Amenuvevega,
Tchakala Ibrahim*,
Sanni Samadou,
Kodom Tomkouani,
Alfa-Sika Mande Seyf-Laye,
Bawa Limam Moctar
Issue:
Volume 13, Issue 1, March 2024
Pages:
9-16
Received:
22 January 2024
Accepted:
18 February 2024
Published:
28 February 2024
Abstract: The present work aims to increase the value of cassava peelings by its transformation in activated carbon. The activated carbon was prepared by chemical activation using 40% of phosphoric acid solution as activation agent with an impregnation rate equal to 1.5 g of acid/g of precursor. The carbonization was carried out at 400°C for 90 minutes. Bohem titration and the Lopez-Ramon method were used to determine the chemical characteristics of the prepared activated carbon (ACCP), while surface area of the sample was estimated by methylene blue and iodine index methods. The best kinetic model that describes the adsorption reaction of MB on ACCP activated carbon is the pseudo-second-order model. Adsorption isotherm was also evaluated. Activated carbon (ACCP) has the following characteristics: pHPZC= 3.9; Iodine index value equal to 914.4 mg/g and methylene blue index value equal to 643.72 mg/l. ACCP has more acid functions (5.95 meq/g) than basic function (1.3 meq/g). The “batch method” was used for pollutant removal and it reveals that the contact time value is equal to 40 minutes. The influence of activated carbon mass on its methylene blue adsorption capacity was studied. The experimental data are in agreement with the Langmuir and Freundlich isotherm models. The maximum adsorption capacity obtained using Langmuir isotherm model was 75.93 mg/g.
Abstract: The present work aims to increase the value of cassava peelings by its transformation in activated carbon. The activated carbon was prepared by chemical activation using 40% of phosphoric acid solution as activation agent with an impregnation rate equal to 1.5 g of acid/g of precursor. The carbonization was carried out at 400°C for 90 minutes. Bohe...
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Research Article
Experimental Study on Adsorption and Corrosion Inhibition Properties of Urena lobata Leaves Extract on Mild Steel in Acidic Medium
Zorbari Kelvin Barineka,
Ngozi Jane Maduelosi*,
Enobong Thompson Umoh
Issue:
Volume 13, Issue 1, March 2024
Pages:
17-27
Received:
26 January 2024
Accepted:
19 February 2024
Published:
13 March 2024
Abstract: The corrosion inhibitive effect of Urena lobata leaves extract on mild steel in 1M HCl solution was investigated via gravimetric, Electrochemical and Surface analyses. Adsorption isotherms were investigated using the Langmuir and Freundlich plots. Phytochemicals of the extract were investigated using Gas Chromatography-Mass Spectrometric (GC-MS) technique. The effect of the leaves extract through immersion time, temperature and concentration on the corrosion inhibition were obtained. The results obtained showed that the increase in extract’s concentration increased the inhibition efficiency and the protection was more on the surface of the metal at lower temperature. Maximum inhibition efficiency of 95.8% was obtained at 2.5g/L extract concentration. Corrosion rate of mild steel increased with temperature increase in the acidic solution. The adsorption process reduced as temperature increased thereby indicating physisorption. The Langmuir isotherms gave the best fit indicating chemisorption. Physical adsorption was confirmed for the leaves extract from observations of inhibition efficiency with temperature, activation energy and enthalpy of adsorption values. Hence indicating that the plant extract has mixed properties. The electrochemical results confirmed the inhibitory ability of the plant extract. The inhibition efficiencies (% IE) were attributed to the phytochemical components (alkaloids, saponins, flavonoids, tannins, cynagenic glycosides) present in the extract. The extracts of Urena lobata are effective corrosion inhibitors of mild steel.
Abstract: The corrosion inhibitive effect of Urena lobata leaves extract on mild steel in 1M HCl solution was investigated via gravimetric, Electrochemical and Surface analyses. Adsorption isotherms were investigated using the Langmuir and Freundlich plots. Phytochemicals of the extract were investigated using Gas Chromatography-Mass Spectrometric (GC-MS) te...
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