muhammad M . Muzakir | Gombe State University, Gombe State, Nigeria (original) (raw)

Papers by muhammad M . Muzakir

Energies, Jun 1, 2020

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti 4+ to Ti 3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm −2 at current density of 0.02 mA cm −2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm −2) at 0.5 mA cm −2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm −2 , as compared to TNTs, retained about 61% at 0.01 mA cm −2. The charge transfer resistance drastically reduced from 6.2 Ω for TNTs to 0.55 Ω for R-TNTs, indicating an improvement in the transfer of electrons and ions across the electrode-electrolyte interface.

Portugaliae Electrochimica Acta, 2019

The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mi... more The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mild steel corrosion in a 1 M NaCl solution, was studied using weight loss, potentiodynamic polarization methods and scanning electron microscopy. Maximum inhibition efficiency of 99.83 % was obtained, at 303 K, for an extract concentration of 3000 mgL-1. The activation and free energies for the inhibition reactions supported the physical adsorption mechanism. The extract adsorption onto the mild steel surface was found to be exothermic, spontaneous, and to obey the Langmuir adsorption model. FT-IR analysis showed the presence of hydroxyl (OH) and carbonyl(C=O) functional groups and aromatic rings in lignin, which are the binding groups that might be responsible for lignin's inhibitive action against mild steel corrosion. Furthermore, SEM analysis revealed that the mild steel surface was affected by lignin's adsorption, due to the formation of a protective film.

RSC Advances, 2021

A facile and simple pulse electrodeposition method was employed to deposit Mn 2 O 3 nanoparticles... more A facile and simple pulse electrodeposition method was employed to deposit Mn 2 O 3 nanoparticles on cathodically reduced titania nanotubes (R-TNTs) at different deposition time in the range of 3-15 min to investigate the influence of mass loading of Mn 2 O 3 on the electrochemical performance of Mn 2 O 3 /R-TNTs nanocomposite for supercapacitor application. Mn 2 O 3 nanoparticles were deposited on circumference of R-TNTs as well as in the nanotubes as revealed by FESEM images for all the deposited time. XPS result confirmed the presence of MnO 2 (Mn 4+) and MnO (Mn 2+) on the Mn 2 O 3 /R-TNTs composite which provide pseudocapacitive behaviour for the electrode. Mass loading of Mn 2 O 3 increased linearly with deposition time as confirmed by EDX analysis. The sample deposited for 12 min exhibits the highest areal capacitance of 51 mF cm À2 (which is 22 times enhancement over R-TNTs) at a current density of 0.1 mA cm À2 and specific capacitance of 325 F g À1 at 6 A g À1. The sample also show a high-rate capability by retaining 80% of its capacitance even at higher current density of 30 A g À1. Interestingly, it retained 98% of the capacitance over 5000 charge discharge cycles at 10 A g À1 after initial drop to 95% at 200th cycles suggesting an excellent long-term chemical stability. A considerably low equivalent series resistance (ESR) and charge transfer resistance (R ct) of 9.6 U and 0.4 U respectively was deduced from electrochemical impedance spectroscopy (EIS) analysis indicating good conductivity and improved charge transfer efficiency of Mn 2 O 3 /R-TNTs nanocomposite.

International Journal of Biological Macromolecules, Jun 1, 2021

The present work developed porous carboxymethyl cellulose (CMC) carbon film from lignocellulosic ... more The present work developed porous carboxymethyl cellulose (CMC) carbon film from lignocellulosic based materials as supercapacitor electrode. Porous CMC carbon films of bamboo (B) and oil palm empty fruit bunch (O) were prepared through simple incipient wetness impregnation method followed by calcination process before incorporation with manganese oxide (Mn2O3). The carbonization produced porous CMC carbon whereby CMCB exhibited higher surface area than CMCO. After Mn2O3 incorporation, the crystallite size of CMCB and CMCO were calculated as 50.09 nm and 42.76 nm, respectively whereas Mn2O3/CMCB and Mn2O3/CMCO composite films were revealed to be 26.71 nm and 35.60 nm in size, respectively. Comparatively, the Mn2O3/CMCB composite film exhibited higher electrochemical performance which was 31.98 mF cm-2 as compared to 24.15 mF cm-2 by Mn2O3/CMCO composite film and both CMC carbon films with fairly stable cycling stability after 1000 charge-discharge cycles. Therefore, it can be highlighted that Mn2O3/CMC composite film as prepared from bamboo and oil palm fruit can potentially become the new electrode materials for supercapacitor application.

This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia ha... more This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia hastate leaves. The proximate analysis shows moisture, ash, lipid, crude protein, crude fiber and carbohydrate contents to be (7.67, 17.67, 5.0, 14.88, 9.33, and 45.45) % respectively. The high percentage of carbohydrates indicates that Leptadenia hastata leaves could served as a good source of energy to the body. The elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS). Calcium recorded the highest concentration of 1845.66 mgKg and Zinc with the lowest concentration of 15.27mgKg. Other elements includes; Na, Fe, K and Mg with concentrations of (72.54, 148.94, 1245.34 and 275.87) mgKg respectively. These results suggest that Leptadenia hastata leaves could served as good source of minerals such as Ca, Fe, and K that are essential for human and livestock.

Greener Journal of Agricultural Sciences, 2014

Energies, 2020

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti4+ to Ti3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm−2 at current density of 0.02 mA cm−2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm−2) at 0.5 mA cm−2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm−2, a...

Journal of Applied Sciences and Environmental Management, Mar 1, 2016

This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed)... more This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed) and Tithonia diversifolia (Mexican Sunflower) using alkali pretreatment method. The raw samples were characterized by some physico-chemical parameters before extraction. Chromolaena odorata gave higher lignin yield and lesser ash content of 15.12 % and 4.22 % respectively compared to Tithonia diversifolia with 7.40 % and 9.56 % respectively. The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the values of ash content (4.22%) and klason lignin (33.65 %) for Chromolaena odorata while ash content (9.56 %) and klason lignin (21.96 %) were obtained from Tithonia diversifolia. The FT-IR spectra of both lignins revealed the presence of syringyl and guaiacyl units. © JASEM

Journal of Applied Sciences and Environmental Management, 2016

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti 4+ to Ti 3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm −2 at current density of 0.02 mA cm −2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm −2) at 0.5 mA cm −2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm −2 , as compared to TNTs, retained about 61% at 0.01 mA cm −2. The charge transfer resistance drastically reduced from 6.2 Ω for TNTs to 0.55 Ω for R-TNTs, indicating an improvement in the transfer of electrons and ions across the electrode-electrolyte interface.

Biodiesel is a renewable, biodegradable and environmentally friendly fuel for use in diesel engin... more Biodiesel is a renewable, biodegradable and environmentally friendly fuel for use in diesel engines. It can overcome the problem associated with fossil fuels such as its non-renewability, polluting nature and its global politics which is a matter of concern to many nations. In this research, biodiesel was produced from the seed oil of baobab (Adansonia digitata) with methanol in the ratio of 5:1 ( v /v) of the oil to alcohol. After the crude oil extract was transesterified, the viscosity of the biodiesel was 0.859cm -2 , the cloud, the pour, and the flash points obtained were 10 o C, 20 o C and 17 o C respectively. From the results it was clear that the produced biodiesel fuel was within the recommended standards of the biodiesel fuel and so can be used as fossil fuel substitute.

The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mi... more The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mild steel corrosion in a 1 M NaCl solution, was studied using weight loss, potentiodynamic polarization methods and scanning electron microscopy. Maximum inhibition efficiency of 99.83 % was obtained, at 303 K, for an extract concentration of 3000 mgL-1. The activation and free energies for the inhibition reactions supported the physical adsorption mechanism. The extract adsorption onto the mild steel surface was found to be exothermic, spontaneous, and to obey the Langmuir adsorption model. FT-IR analysis showed the presence of hydroxyl (OH) and carbonyl(C=O) functional groups and aromatic rings in lignin, which are the binding groups that might be responsible for lignin's inhibitive action against mild steel corrosion. Furthermore, SEM analysis revealed that the mild steel surface was affected by lignin's adsorption, due to the formation of a protective film. Introduction Mild steel is one of the frequently used structural materials for storage tanks, reaction vessels, pipelines, and so on, in chemical and allied industries. During certain operations such as cleaning, pickling, de-scaling or even transportation, mild steel may come in contact with a sodium chloride solution, and get severely corroded [1]. In order to reduce the menace caused by the corrosion of industrial installations, several steps have been adopted. However, one of the best options available for protecting metals against corrosion involves the use of corrosion inhibitors. Corrosion inhibitors are widely used in industry to reduce the corrosion rate of metals and alloys in contact with aggressive environments [2]. These inhibitors can be adsorbed onto metal surfaces, block the active sites, and decrease the corrosion rate. The adsorption ability of inhibitors onto the metal surface depends on the metal's nature and surface charge, chemical composition

This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed)... more This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed) and Tithonia diversifolia (Mexican Sunflower) using alkali pretreatment method. The raw samples were characterized by some physico-chemical parameters before extraction. Chromolaena odorata gave higher lignin yield and lesser ash content of 15.12 % and 4.22 % respectively compared to Tithonia diversifolia with 7.40 % and 9.56 % respectively. The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the values of ash content (4.22%) and klason lignin (33.65 %) for Chromolaena odorata while ash content (9.56 %) and klason lignin (21.96 %) were obtained from Tithonia diversifolia. The FT-IR spectra of both lignins revealed the presence of syringyl and guaiacyl units. © JASEM http://dx.doi.org/10.4314/jasem.v19i4.29

This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia ha... more This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia hastate leaves. The proximate analysis shows moisture, ash, lipid, crude protein, crude fiber and carbohydrate contents to be (7.67, 17.67, 5.0, 14.88, 9.33, and 45.45) % respectively. The high percentage of carbohydrates indicates that Leptadenia hastata leaves could served as a good source of energy to the body. The elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS). Calcium recorded the highest concentration of 1845.66 mgKg-1 and Zinc with the lowest concentration of 15.27mgKg-1. Other elements includes; Na, Fe, K and Mg with concentrations of (72.54, 148.94, 1245.34 and 275.87) mgKg-1 respectively. These results suggest that Leptadenia hastata leaves could served as good source of minerals such as Ca, Fe, and K that are essential for human and livestock.

The toxic effects of synthetic corrosion inhibitors have led to the search for naturally occurrin... more The toxic effects of synthetic corrosion inhibitors have led to the search for naturally occurring substances which are not only readily available but are also environmentally friendly. Therefore, this study investigates the inhibition efficacy of acid extract of Groundnut Shell (GS) on mild steel corrosion in 1 M HCl using weight loss method. Experiments were performed by varying inhibitor concentrations, at different temperatures. The inhibition efficiency increased with an increase in inhibitor concentration, but is not consistent with increase in temperature. Maximum inhibition efficiency of 89.89 % was obtained at 318 K with 2500 mg/L inhibitor concentration. Thermodynamic studies revealed that the corrosion inhibition may be due to the spontaneous physical adsorption of the Groundnut shell constituents on the surface of mild steel. Experimental data fitted well into the Langmuir adsorption isotherm. FT-IR analysis of the GS revealed the presence of hydroxyl (OH), amine (NH) and carbonyl functional groups which may act as adsorption sites.

Corrosion has been chronic problem to industries and has increased cost of production. Lignin is ... more Corrosion has been chronic problem to industries and has increased cost of production. Lignin is the second most natural organic polymer on the earth and it can be obtained from the wastes of wood pulping processing in the form of black liquor. The inhibition efficiency of lignin on the corrosion of mild steel in 1 M HCl have been evaluated by conventional weight loss method, and surface analysis using 500-5000 mg/L (w/v) inhibitor concentration in temperature range of 303-343 K. Maximum inhibition efficiency of 92.39 % was obtained with optimum inhibitor concentration of 4000 mg/L at 303 K. The activation and free energies for the inhibition reactions support the mechanism of physical adsorption. The adsorption of lignin extract on mild steel surface is endothermic, spontaneous and consistent with the Langmuir adsorption isotherm at all studied temperatures. FT-IR and SEM analyses confirmed that the surface of mild steel was affected by the adsorption of lignin onto the surface to form ferric-lignin compounds.

Energies, Jun 1, 2020

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti 4+ to Ti 3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm −2 at current density of 0.02 mA cm −2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm −2) at 0.5 mA cm −2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm −2 , as compared to TNTs, retained about 61% at 0.01 mA cm −2. The charge transfer resistance drastically reduced from 6.2 Ω for TNTs to 0.55 Ω for R-TNTs, indicating an improvement in the transfer of electrons and ions across the electrode-electrolyte interface.

Portugaliae Electrochimica Acta, 2019

The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mi... more The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mild steel corrosion in a 1 M NaCl solution, was studied using weight loss, potentiodynamic polarization methods and scanning electron microscopy. Maximum inhibition efficiency of 99.83 % was obtained, at 303 K, for an extract concentration of 3000 mgL-1. The activation and free energies for the inhibition reactions supported the physical adsorption mechanism. The extract adsorption onto the mild steel surface was found to be exothermic, spontaneous, and to obey the Langmuir adsorption model. FT-IR analysis showed the presence of hydroxyl (OH) and carbonyl(C=O) functional groups and aromatic rings in lignin, which are the binding groups that might be responsible for lignin's inhibitive action against mild steel corrosion. Furthermore, SEM analysis revealed that the mild steel surface was affected by lignin's adsorption, due to the formation of a protective film.

RSC Advances, 2021

A facile and simple pulse electrodeposition method was employed to deposit Mn 2 O 3 nanoparticles... more A facile and simple pulse electrodeposition method was employed to deposit Mn 2 O 3 nanoparticles on cathodically reduced titania nanotubes (R-TNTs) at different deposition time in the range of 3-15 min to investigate the influence of mass loading of Mn 2 O 3 on the electrochemical performance of Mn 2 O 3 /R-TNTs nanocomposite for supercapacitor application. Mn 2 O 3 nanoparticles were deposited on circumference of R-TNTs as well as in the nanotubes as revealed by FESEM images for all the deposited time. XPS result confirmed the presence of MnO 2 (Mn 4+) and MnO (Mn 2+) on the Mn 2 O 3 /R-TNTs composite which provide pseudocapacitive behaviour for the electrode. Mass loading of Mn 2 O 3 increased linearly with deposition time as confirmed by EDX analysis. The sample deposited for 12 min exhibits the highest areal capacitance of 51 mF cm À2 (which is 22 times enhancement over R-TNTs) at a current density of 0.1 mA cm À2 and specific capacitance of 325 F g À1 at 6 A g À1. The sample also show a high-rate capability by retaining 80% of its capacitance even at higher current density of 30 A g À1. Interestingly, it retained 98% of the capacitance over 5000 charge discharge cycles at 10 A g À1 after initial drop to 95% at 200th cycles suggesting an excellent long-term chemical stability. A considerably low equivalent series resistance (ESR) and charge transfer resistance (R ct) of 9.6 U and 0.4 U respectively was deduced from electrochemical impedance spectroscopy (EIS) analysis indicating good conductivity and improved charge transfer efficiency of Mn 2 O 3 /R-TNTs nanocomposite.

International Journal of Biological Macromolecules, Jun 1, 2021

The present work developed porous carboxymethyl cellulose (CMC) carbon film from lignocellulosic ... more The present work developed porous carboxymethyl cellulose (CMC) carbon film from lignocellulosic based materials as supercapacitor electrode. Porous CMC carbon films of bamboo (B) and oil palm empty fruit bunch (O) were prepared through simple incipient wetness impregnation method followed by calcination process before incorporation with manganese oxide (Mn2O3). The carbonization produced porous CMC carbon whereby CMCB exhibited higher surface area than CMCO. After Mn2O3 incorporation, the crystallite size of CMCB and CMCO were calculated as 50.09 nm and 42.76 nm, respectively whereas Mn2O3/CMCB and Mn2O3/CMCO composite films were revealed to be 26.71 nm and 35.60 nm in size, respectively. Comparatively, the Mn2O3/CMCB composite film exhibited higher electrochemical performance which was 31.98 mF cm-2 as compared to 24.15 mF cm-2 by Mn2O3/CMCO composite film and both CMC carbon films with fairly stable cycling stability after 1000 charge-discharge cycles. Therefore, it can be highlighted that Mn2O3/CMC composite film as prepared from bamboo and oil palm fruit can potentially become the new electrode materials for supercapacitor application.

This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia ha... more This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia hastate leaves. The proximate analysis shows moisture, ash, lipid, crude protein, crude fiber and carbohydrate contents to be (7.67, 17.67, 5.0, 14.88, 9.33, and 45.45) % respectively. The high percentage of carbohydrates indicates that Leptadenia hastata leaves could served as a good source of energy to the body. The elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS). Calcium recorded the highest concentration of 1845.66 mgKg and Zinc with the lowest concentration of 15.27mgKg. Other elements includes; Na, Fe, K and Mg with concentrations of (72.54, 148.94, 1245.34 and 275.87) mgKg respectively. These results suggest that Leptadenia hastata leaves could served as good source of minerals such as Ca, Fe, and K that are essential for human and livestock.

Greener Journal of Agricultural Sciences, 2014

Energies, 2020

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti4+ to Ti3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm−2 at current density of 0.02 mA cm−2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm−2) at 0.5 mA cm−2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm−2, a...

Journal of Applied Sciences and Environmental Management, Mar 1, 2016

This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed)... more This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed) and Tithonia diversifolia (Mexican Sunflower) using alkali pretreatment method. The raw samples were characterized by some physico-chemical parameters before extraction. Chromolaena odorata gave higher lignin yield and lesser ash content of 15.12 % and 4.22 % respectively compared to Tithonia diversifolia with 7.40 % and 9.56 % respectively. The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the values of ash content (4.22%) and klason lignin (33.65 %) for Chromolaena odorata while ash content (9.56 %) and klason lignin (21.96 %) were obtained from Tithonia diversifolia. The FT-IR spectra of both lignins revealed the presence of syringyl and guaiacyl units. © JASEM

Journal of Applied Sciences and Environmental Management, 2016

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic... more In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti 4+ to Ti 3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm −2 at current density of 0.02 mA cm −2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm −2) at 0.5 mA cm −2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm −2 , as compared to TNTs, retained about 61% at 0.01 mA cm −2. The charge transfer resistance drastically reduced from 6.2 Ω for TNTs to 0.55 Ω for R-TNTs, indicating an improvement in the transfer of electrons and ions across the electrode-electrolyte interface.

Biodiesel is a renewable, biodegradable and environmentally friendly fuel for use in diesel engin... more Biodiesel is a renewable, biodegradable and environmentally friendly fuel for use in diesel engines. It can overcome the problem associated with fossil fuels such as its non-renewability, polluting nature and its global politics which is a matter of concern to many nations. In this research, biodiesel was produced from the seed oil of baobab (Adansonia digitata) with methanol in the ratio of 5:1 ( v /v) of the oil to alcohol. After the crude oil extract was transesterified, the viscosity of the biodiesel was 0.859cm -2 , the cloud, the pour, and the flash points obtained were 10 o C, 20 o C and 17 o C respectively. From the results it was clear that the produced biodiesel fuel was within the recommended standards of the biodiesel fuel and so can be used as fossil fuel substitute.

The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mi... more The inhibitive action of Chromolaena odorata stems extract, in various concentrations, against mild steel corrosion in a 1 M NaCl solution, was studied using weight loss, potentiodynamic polarization methods and scanning electron microscopy. Maximum inhibition efficiency of 99.83 % was obtained, at 303 K, for an extract concentration of 3000 mgL-1. The activation and free energies for the inhibition reactions supported the physical adsorption mechanism. The extract adsorption onto the mild steel surface was found to be exothermic, spontaneous, and to obey the Langmuir adsorption model. FT-IR analysis showed the presence of hydroxyl (OH) and carbonyl(C=O) functional groups and aromatic rings in lignin, which are the binding groups that might be responsible for lignin's inhibitive action against mild steel corrosion. Furthermore, SEM analysis revealed that the mild steel surface was affected by lignin's adsorption, due to the formation of a protective film. Introduction Mild steel is one of the frequently used structural materials for storage tanks, reaction vessels, pipelines, and so on, in chemical and allied industries. During certain operations such as cleaning, pickling, de-scaling or even transportation, mild steel may come in contact with a sodium chloride solution, and get severely corroded [1]. In order to reduce the menace caused by the corrosion of industrial installations, several steps have been adopted. However, one of the best options available for protecting metals against corrosion involves the use of corrosion inhibitors. Corrosion inhibitors are widely used in industry to reduce the corrosion rate of metals and alloys in contact with aggressive environments [2]. These inhibitors can be adsorbed onto metal surfaces, block the active sites, and decrease the corrosion rate. The adsorption ability of inhibitors onto the metal surface depends on the metal's nature and surface charge, chemical composition

This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed)... more This study dealt with isolation of lignin from soft woods namely; Chromolaena odorata (Siam Weed) and Tithonia diversifolia (Mexican Sunflower) using alkali pretreatment method. The raw samples were characterized by some physico-chemical parameters before extraction. Chromolaena odorata gave higher lignin yield and lesser ash content of 15.12 % and 4.22 % respectively compared to Tithonia diversifolia with 7.40 % and 9.56 % respectively. The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the values of ash content (4.22%) and klason lignin (33.65 %) for Chromolaena odorata while ash content (9.56 %) and klason lignin (21.96 %) were obtained from Tithonia diversifolia. The FT-IR spectra of both lignins revealed the presence of syringyl and guaiacyl units. © JASEM http://dx.doi.org/10.4314/jasem.v19i4.29

This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia ha... more This paper aimed at investigating the chemical compositions and mineral contents of Leptadenia hastate leaves. The proximate analysis shows moisture, ash, lipid, crude protein, crude fiber and carbohydrate contents to be (7.67, 17.67, 5.0, 14.88, 9.33, and 45.45) % respectively. The high percentage of carbohydrates indicates that Leptadenia hastata leaves could served as a good source of energy to the body. The elemental analysis was carried out using Atomic Absorption Spectrophotometer (AAS). Calcium recorded the highest concentration of 1845.66 mgKg-1 and Zinc with the lowest concentration of 15.27mgKg-1. Other elements includes; Na, Fe, K and Mg with concentrations of (72.54, 148.94, 1245.34 and 275.87) mgKg-1 respectively. These results suggest that Leptadenia hastata leaves could served as good source of minerals such as Ca, Fe, and K that are essential for human and livestock.

The toxic effects of synthetic corrosion inhibitors have led to the search for naturally occurrin... more The toxic effects of synthetic corrosion inhibitors have led to the search for naturally occurring substances which are not only readily available but are also environmentally friendly. Therefore, this study investigates the inhibition efficacy of acid extract of Groundnut Shell (GS) on mild steel corrosion in 1 M HCl using weight loss method. Experiments were performed by varying inhibitor concentrations, at different temperatures. The inhibition efficiency increased with an increase in inhibitor concentration, but is not consistent with increase in temperature. Maximum inhibition efficiency of 89.89 % was obtained at 318 K with 2500 mg/L inhibitor concentration. Thermodynamic studies revealed that the corrosion inhibition may be due to the spontaneous physical adsorption of the Groundnut shell constituents on the surface of mild steel. Experimental data fitted well into the Langmuir adsorption isotherm. FT-IR analysis of the GS revealed the presence of hydroxyl (OH), amine (NH) and carbonyl functional groups which may act as adsorption sites.

Corrosion has been chronic problem to industries and has increased cost of production. Lignin is ... more Corrosion has been chronic problem to industries and has increased cost of production. Lignin is the second most natural organic polymer on the earth and it can be obtained from the wastes of wood pulping processing in the form of black liquor. The inhibition efficiency of lignin on the corrosion of mild steel in 1 M HCl have been evaluated by conventional weight loss method, and surface analysis using 500-5000 mg/L (w/v) inhibitor concentration in temperature range of 303-343 K. Maximum inhibition efficiency of 92.39 % was obtained with optimum inhibitor concentration of 4000 mg/L at 303 K. The activation and free energies for the inhibition reactions support the mechanism of physical adsorption. The adsorption of lignin extract on mild steel surface is endothermic, spontaneous and consistent with the Langmuir adsorption isotherm at all studied temperatures. FT-IR and SEM analyses confirmed that the surface of mild steel was affected by the adsorption of lignin onto the surface to form ferric-lignin compounds.