Talal Aljohani - Academia.edu (original) (raw)

Papers by Talal Aljohani

Authorea (Authorea), Apr 8, 2021

This study aims to investigate the effect of the processing parameters in plasma electrolytic oxi... more This study aims to investigate the effect of the processing parameters in plasma electrolytic oxidation (PEO) on the corrosion resistance of magnesium alloy type AZ91. The PEO coatings were prepared on the samples using alkaline-based electrolyte. Both

International Journal of Electrochemical Science, Aug 1, 2016

High photoconversion efficiency for photoelectrochemical water splitting was obtained using nanoc... more High photoconversion efficiency for photoelectrochemical water splitting was obtained using nanocaves TiO 2 and highly uniformed TiO 2 nanotubes. The photoanodes were synthesized via electrochemical anodization of a titanium foil in a glycerol-based solution containing NH 4 F at 10 V. Pulse electrodeposition was used to incorporate Cu ions into the uniform TiO 2 nanotubes. The photoconversion efficiency performance was examined under simulated visible light illumination (ʎ ≥ 380 nm) in a 1 M solution of NaOH. The photocurrent density, the Mott-Schottky, the EIS, and the photoconversion efficiency measurements were determined. The highest photocurrent density i.e. 5.77 mA cm-2 at 1.23 V vs. RHE was obtained from nanocaves TiO 2 photoanode. The incorporation of Cu resulted in a reduction in photocatalytic activity of the oxygen evaluation reaction (OER) and an increase of the hydrogen evolution reaction (HER).

Materials, Sep 2, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Meeting abstracts, 2016

Titanium oxide nanotubes (NTs) were synthesised using the electrochemical anodisation approach in... more Titanium oxide nanotubes (NTs) were synthesised using the electrochemical anodisation approach in a glycerol-based solution containing NH4F at 10 volts. Pulse electrodeposition (PED) was applied to decorate the NTs with copper. The results reveal that the morphology of the porous nanotubes plays a significant role in the efficiency of photoelectrochemical water splitting. The highest photocurrent density obtained is 5.77 mA cm-2 at 1.23 V vs. RHE for the annealed pure TiO2 nanotubes (NTs) illuminated with a solar simulator under visible light (ʎ≥ 385 nm). The Cu doped TiO2 nanotubes showed lower photocurrent density compared to the pure TiO2 nanotubes (NTs) despite an increase in the carrier density (ND) concentration after Cu doping. The maximum photon conversion efficiency achieved is 1.1 % at 1.23 vs. RHE, which is the highest conversion efficiency ever reported under such conditions. Figure 1

Scientific Reports, Sep 6, 2018

The grain boundaries in superconducting MgB 2 are known to form effective magnetic flux pinning s... more The grain boundaries in superconducting MgB 2 are known to form effective magnetic flux pinning sites and, consequently, bulk MgB 2 containing a fine-grain microstructure fabricated from nanoscale Mg and B precursor powders exhibits good magnetic field-trapping performance below 20 K. We report here that the trapped field of MgB 2 bulk superconductors fabricated by an infiltration and growth process to yield a dense, pore-free microstructure, can be enhanced significantly by carbon-doping, which increases intra-band scattering within the superconducting grains. A maximum trapped field of 4.15 T has been measured at 7.5 K at the centre of a five-sample stack of Mg(B 1−xi C xi) 2 bulk superconductors processed by infiltration and growth, which not only represents a ~40% increase in trapped field observed compared to undoped bulk MgB 2 , but also is the highest trapped field reported to date in MgB 2 samples processed under ambient pressure. The trapped field is observed to decay at a rate of <2%/day at 10 K, which suggests that bulk MgB 2 superconductors fabricated using the infiltration and growth technique can be used potentially to generate stable, high magnetic fields for a variety of engineering applications.

Journal of Saudi Chemical Society

Research and reviews: journal of material sciences, Sep 24, 2018

P hotoelectrochemical water splitting is a sustainable pathway to produce clean hydrogen fuel. Du... more P hotoelectrochemical water splitting is a sustainable pathway to produce clean hydrogen fuel. Due to the slow kinetics of the oxidation evolution reaction (OER), the realization of an efficient photoanode remains a great challenge. To lower the overpotential (η) for OER, crystalized and amorphous metal oxides integrated with photoanodes have been recently utilized as excellent co-catalysts. Considering the high cost of noble metal oxide catalysts due to their scarcity, such as IrO 2 and RuO 2 , earthabundant transition metal oxides, such as Ni-based nanowire electrocatalysts, hold promises for cost-effective and yet efficient water splitting. Compared to the limitation in charge extraction capability and light blocking of the conventional particlebased co-catalysts, the flexibility of engineering the morphology and the surface properties of templated Ni-based nanowire co-catalyts is enormous. That is, highly-ordered templated Ni-based nanowire co-catalyts can be advantageous for their light trapping, large surface-to-volume ratio, rapid carrier extractions, anti-reflection properties besides lowering the overpotential (η). We demonstrate that engineering the morphology of templated Ni-based nanowire co-catalysts on Si photoanode can lead to efficient OER. We shall further show that optimizing the surface properties of the nanowire co-catalysts by incorporating other divalent metal dopants such as Co and Fe can lead to efficient and stable water oxidation with low overpotential. In this work, Ni-based nanowires arrays are deposited electrochemically and physically on various substrates using ultrathin anodic aluminum oxide (AAO) template. The length, diameter and thickness of nanowires can be varied depending on the pores' dimensions and thickness of the AAO membrane leading to controllable co-catalysts morphology. Shown in figure is the scanning electron microscopy (SEM) image of pristine NiO nanowires deposited electrochemically on ITO substrate. We shall further show that by optimizing the surface charge properties through the deposition techniques and incorporating Co and Fe dopants, the overpotential for OER can be substantially reduced. Full electrochemical properties using three-electrode configuration in NaOH electrolyte will be presented. Further elemental and structural properties of the nanowire co-catalysts shall be thoroughly discussed. In brief, the use of such nanowire co-catalysts integrated with Si photoanode for high efficient and stable photoelectrochemical water splitting shall be demonstrated. This detailed study confirms that the morphology and surface Ni-based nanowire co-catalysts doped with Co and Fe can lead to lower OER overpotential.

South African Journal of Chemical Engineering

Journal of Bio- and Tribo-Corrosion

Frontiers in Materials, Jan 30, 2023

In this study, novel nanostructures based on Ni-MOF/polysulfone nanofibers were fabricated by mic... more In this study, novel nanostructures based on Ni-MOF/polysulfone nanofibers were fabricated by microwave-assisted electrospinning method. The final Ni-MOF/polysulfone fibrous nanostructure were immobilized on SiO 2 substrates with high physicho-chemical properties. These nanostructures with an average diameter of 20 nm and a specific surface area of 1690 m 2 /g were used as novel adsorption for CH 4 gas adsorption. It seems that the integration of novel Ni-MOF compounds into the fibrous network has differentiated these materials from previous samples. Since the experimental parameters significantly affect the specific surface area, the parameters including voltage, concentration, and distance between the collector and source are designed by the fractional factorial method. The results were optimized by contour plots, ANOVA and surface plots, theoretically. The results show that the sample has an adsorption rate of about 5.14 mmoL/g. The improved CH 4 gas adsorption performance is attributed to the large specific surface area and porous nature of the Ni-MOF/Ps nanostructure which is more convenient and accessible for CH4 gas adsorption.

Materials

Hundreds of billions of aluminium-based cans are manufactured and used every year worldwide inclu... more Hundreds of billions of aluminium-based cans are manufactured and used every year worldwide including those containing soft drinks. This study investigates and evaluates the performance and quality of two well-known energy and soft drinks brands, Green Cola and Red Bull. Recent health hazards and concerns have been associated with aluminium leakage and bisphenol A (BPA) dissociation from the can’s internal protective coating. The cans were examined under four conditions, including coated and uncoated samples, the soft drink’s main solution, and 0.1 M acetic acid solution. Electrochemical measurements such as potentiodynamic polarization and impedance spectroscopy (EIS), element analyses using inductively coupled plasma optical emission spectrometry (ICP-OES), and energy dispersive X-ray spectroscopy (EDS) were performed. In addition, sample characterization by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) were employed to comprehensively study and analy...

Materials

In this study, the corrosion performance of AA2014 aluminum alloy was enhanced by coating the all... more In this study, the corrosion performance of AA2014 aluminum alloy was enhanced by coating the alloy with a layer containing silica (SiC) that was formed by the plasma electrolytic oxidation (PEO) process. The PEO process was performed with different electrical parameters (frequency, current mode, and duty ratio) and both with and without SiC to investigate the microstructural and electrochemical differences in the coated samples produced from the process. The microstructure and composition of the PEO coatings were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). A potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behavior of the AA2014-PEO-coated samples. The potentiodynamic polarization showed that the SiC-PEO-coated samples had a significantly decreased corrosion rate (99.8%) compared with the uncoated AA2014 Al alloy. Our results sho...

Journal of Saudi Chemical Society

Materials

Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applicat... more Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applications where biodegradability is critical. The combination of their good biocompatibility, improved strength, and low cytotoxicity makes them great candidates for medical implants. This research investigation is focused on providing further insight into the effects of equal channel angular processing (ECAP) on the corrosion behavior, microstructure evolution, and mechanical properties of a biodegradable ZK30 alloy. Billets of Mg-3Zn-0.6 Zr (ZK30) alloy were processed through ECAP up to 4 passes of route Bc (rotating the billets 90° in the same direction between the subsequent passes) at 250 °C. Electron back-scatter diffraction (EBSD) was utilized to investigate the microstructural evolution as well as the crystallographic texture. Several electrochemical measurements were carried out on both a simulated body fluid and a 3.5% sodium chloride (NaCl) solution. Mechanical properties such as V...

Materials Chemistry and Physics

Journal of Electrochemical Science and Engineering, 2022

Coiled tubing (CT) is widely used in the oil and gas industry. However, corrosion-related failure... more Coiled tubing (CT) is widely used in the oil and gas industry. However, corrosion-related failures are frequently reported. Research into the causes of failures leads to improvement in the design of components and processes. In this study, a new CT sample and a CT sample with perforated wall that had failed after a few acidizing operations were selected for analysis. Scanning electron microscope (SEM) images at the fracture site showed that CT damage was caused by the low cycle fatigue. In addition, light and scanning electron microscopy (SEM) showed that a corrosion pit acted as the initiator of the crack. Elemental analysis using energy dispersive X-ray spectroscopy (EDS) indicated the presence of an iron oxide layer and a layer associated with the Sb containing inhibitor. The corrosion damage investigation showed that the internal CT wall pits likely formed during storage due to the acidizing operations in the areas where the remaining liquid was still at the tube bottom.

The Minerals, Metals & Materials Series, 2022

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022

Authorea (Authorea), Apr 8, 2021

This study aims to investigate the effect of the processing parameters in plasma electrolytic oxi... more This study aims to investigate the effect of the processing parameters in plasma electrolytic oxidation (PEO) on the corrosion resistance of magnesium alloy type AZ91. The PEO coatings were prepared on the samples using alkaline-based electrolyte. Both

International Journal of Electrochemical Science, Aug 1, 2016

High photoconversion efficiency for photoelectrochemical water splitting was obtained using nanoc... more High photoconversion efficiency for photoelectrochemical water splitting was obtained using nanocaves TiO 2 and highly uniformed TiO 2 nanotubes. The photoanodes were synthesized via electrochemical anodization of a titanium foil in a glycerol-based solution containing NH 4 F at 10 V. Pulse electrodeposition was used to incorporate Cu ions into the uniform TiO 2 nanotubes. The photoconversion efficiency performance was examined under simulated visible light illumination (ʎ ≥ 380 nm) in a 1 M solution of NaOH. The photocurrent density, the Mott-Schottky, the EIS, and the photoconversion efficiency measurements were determined. The highest photocurrent density i.e. 5.77 mA cm-2 at 1.23 V vs. RHE was obtained from nanocaves TiO 2 photoanode. The incorporation of Cu resulted in a reduction in photocatalytic activity of the oxygen evaluation reaction (OER) and an increase of the hydrogen evolution reaction (HER).

Materials, Sep 2, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Meeting abstracts, 2016

Titanium oxide nanotubes (NTs) were synthesised using the electrochemical anodisation approach in... more Titanium oxide nanotubes (NTs) were synthesised using the electrochemical anodisation approach in a glycerol-based solution containing NH4F at 10 volts. Pulse electrodeposition (PED) was applied to decorate the NTs with copper. The results reveal that the morphology of the porous nanotubes plays a significant role in the efficiency of photoelectrochemical water splitting. The highest photocurrent density obtained is 5.77 mA cm-2 at 1.23 V vs. RHE for the annealed pure TiO2 nanotubes (NTs) illuminated with a solar simulator under visible light (ʎ≥ 385 nm). The Cu doped TiO2 nanotubes showed lower photocurrent density compared to the pure TiO2 nanotubes (NTs) despite an increase in the carrier density (ND) concentration after Cu doping. The maximum photon conversion efficiency achieved is 1.1 % at 1.23 vs. RHE, which is the highest conversion efficiency ever reported under such conditions. Figure 1

Scientific Reports, Sep 6, 2018

The grain boundaries in superconducting MgB 2 are known to form effective magnetic flux pinning s... more The grain boundaries in superconducting MgB 2 are known to form effective magnetic flux pinning sites and, consequently, bulk MgB 2 containing a fine-grain microstructure fabricated from nanoscale Mg and B precursor powders exhibits good magnetic field-trapping performance below 20 K. We report here that the trapped field of MgB 2 bulk superconductors fabricated by an infiltration and growth process to yield a dense, pore-free microstructure, can be enhanced significantly by carbon-doping, which increases intra-band scattering within the superconducting grains. A maximum trapped field of 4.15 T has been measured at 7.5 K at the centre of a five-sample stack of Mg(B 1−xi C xi) 2 bulk superconductors processed by infiltration and growth, which not only represents a ~40% increase in trapped field observed compared to undoped bulk MgB 2 , but also is the highest trapped field reported to date in MgB 2 samples processed under ambient pressure. The trapped field is observed to decay at a rate of <2%/day at 10 K, which suggests that bulk MgB 2 superconductors fabricated using the infiltration and growth technique can be used potentially to generate stable, high magnetic fields for a variety of engineering applications.

Journal of Saudi Chemical Society

Research and reviews: journal of material sciences, Sep 24, 2018

P hotoelectrochemical water splitting is a sustainable pathway to produce clean hydrogen fuel. Du... more P hotoelectrochemical water splitting is a sustainable pathway to produce clean hydrogen fuel. Due to the slow kinetics of the oxidation evolution reaction (OER), the realization of an efficient photoanode remains a great challenge. To lower the overpotential (η) for OER, crystalized and amorphous metal oxides integrated with photoanodes have been recently utilized as excellent co-catalysts. Considering the high cost of noble metal oxide catalysts due to their scarcity, such as IrO 2 and RuO 2 , earthabundant transition metal oxides, such as Ni-based nanowire electrocatalysts, hold promises for cost-effective and yet efficient water splitting. Compared to the limitation in charge extraction capability and light blocking of the conventional particlebased co-catalysts, the flexibility of engineering the morphology and the surface properties of templated Ni-based nanowire co-catalyts is enormous. That is, highly-ordered templated Ni-based nanowire co-catalyts can be advantageous for their light trapping, large surface-to-volume ratio, rapid carrier extractions, anti-reflection properties besides lowering the overpotential (η). We demonstrate that engineering the morphology of templated Ni-based nanowire co-catalysts on Si photoanode can lead to efficient OER. We shall further show that optimizing the surface properties of the nanowire co-catalysts by incorporating other divalent metal dopants such as Co and Fe can lead to efficient and stable water oxidation with low overpotential. In this work, Ni-based nanowires arrays are deposited electrochemically and physically on various substrates using ultrathin anodic aluminum oxide (AAO) template. The length, diameter and thickness of nanowires can be varied depending on the pores' dimensions and thickness of the AAO membrane leading to controllable co-catalysts morphology. Shown in figure is the scanning electron microscopy (SEM) image of pristine NiO nanowires deposited electrochemically on ITO substrate. We shall further show that by optimizing the surface charge properties through the deposition techniques and incorporating Co and Fe dopants, the overpotential for OER can be substantially reduced. Full electrochemical properties using three-electrode configuration in NaOH electrolyte will be presented. Further elemental and structural properties of the nanowire co-catalysts shall be thoroughly discussed. In brief, the use of such nanowire co-catalysts integrated with Si photoanode for high efficient and stable photoelectrochemical water splitting shall be demonstrated. This detailed study confirms that the morphology and surface Ni-based nanowire co-catalysts doped with Co and Fe can lead to lower OER overpotential.

South African Journal of Chemical Engineering

Journal of Bio- and Tribo-Corrosion

Frontiers in Materials, Jan 30, 2023

In this study, novel nanostructures based on Ni-MOF/polysulfone nanofibers were fabricated by mic... more In this study, novel nanostructures based on Ni-MOF/polysulfone nanofibers were fabricated by microwave-assisted electrospinning method. The final Ni-MOF/polysulfone fibrous nanostructure were immobilized on SiO 2 substrates with high physicho-chemical properties. These nanostructures with an average diameter of 20 nm and a specific surface area of 1690 m 2 /g were used as novel adsorption for CH 4 gas adsorption. It seems that the integration of novel Ni-MOF compounds into the fibrous network has differentiated these materials from previous samples. Since the experimental parameters significantly affect the specific surface area, the parameters including voltage, concentration, and distance between the collector and source are designed by the fractional factorial method. The results were optimized by contour plots, ANOVA and surface plots, theoretically. The results show that the sample has an adsorption rate of about 5.14 mmoL/g. The improved CH 4 gas adsorption performance is attributed to the large specific surface area and porous nature of the Ni-MOF/Ps nanostructure which is more convenient and accessible for CH4 gas adsorption.

Materials

Hundreds of billions of aluminium-based cans are manufactured and used every year worldwide inclu... more Hundreds of billions of aluminium-based cans are manufactured and used every year worldwide including those containing soft drinks. This study investigates and evaluates the performance and quality of two well-known energy and soft drinks brands, Green Cola and Red Bull. Recent health hazards and concerns have been associated with aluminium leakage and bisphenol A (BPA) dissociation from the can’s internal protective coating. The cans were examined under four conditions, including coated and uncoated samples, the soft drink’s main solution, and 0.1 M acetic acid solution. Electrochemical measurements such as potentiodynamic polarization and impedance spectroscopy (EIS), element analyses using inductively coupled plasma optical emission spectrometry (ICP-OES), and energy dispersive X-ray spectroscopy (EDS) were performed. In addition, sample characterization by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD) were employed to comprehensively study and analy...

Materials

In this study, the corrosion performance of AA2014 aluminum alloy was enhanced by coating the all... more In this study, the corrosion performance of AA2014 aluminum alloy was enhanced by coating the alloy with a layer containing silica (SiC) that was formed by the plasma electrolytic oxidation (PEO) process. The PEO process was performed with different electrical parameters (frequency, current mode, and duty ratio) and both with and without SiC to investigate the microstructural and electrochemical differences in the coated samples produced from the process. The microstructure and composition of the PEO coatings were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). A potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behavior of the AA2014-PEO-coated samples. The potentiodynamic polarization showed that the SiC-PEO-coated samples had a significantly decreased corrosion rate (99.8%) compared with the uncoated AA2014 Al alloy. Our results sho...

Journal of Saudi Chemical Society

Materials

Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applicat... more Magnesium-Zinc-Zirconium (Mg-Zn-Zr) alloys have caught considerable attention in medical applications where biodegradability is critical. The combination of their good biocompatibility, improved strength, and low cytotoxicity makes them great candidates for medical implants. This research investigation is focused on providing further insight into the effects of equal channel angular processing (ECAP) on the corrosion behavior, microstructure evolution, and mechanical properties of a biodegradable ZK30 alloy. Billets of Mg-3Zn-0.6 Zr (ZK30) alloy were processed through ECAP up to 4 passes of route Bc (rotating the billets 90° in the same direction between the subsequent passes) at 250 °C. Electron back-scatter diffraction (EBSD) was utilized to investigate the microstructural evolution as well as the crystallographic texture. Several electrochemical measurements were carried out on both a simulated body fluid and a 3.5% sodium chloride (NaCl) solution. Mechanical properties such as V...

Materials Chemistry and Physics

Journal of Electrochemical Science and Engineering, 2022

Coiled tubing (CT) is widely used in the oil and gas industry. However, corrosion-related failure... more Coiled tubing (CT) is widely used in the oil and gas industry. However, corrosion-related failures are frequently reported. Research into the causes of failures leads to improvement in the design of components and processes. In this study, a new CT sample and a CT sample with perforated wall that had failed after a few acidizing operations were selected for analysis. Scanning electron microscope (SEM) images at the fracture site showed that CT damage was caused by the low cycle fatigue. In addition, light and scanning electron microscopy (SEM) showed that a corrosion pit acted as the initiator of the crack. Elemental analysis using energy dispersive X-ray spectroscopy (EDS) indicated the presence of an iron oxide layer and a layer associated with the Sb containing inhibitor. The corrosion damage investigation showed that the internal CT wall pits likely formed during storage due to the acidizing operations in the areas where the remaining liquid was still at the tube bottom.

The Minerals, Metals & Materials Series, 2022

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022