Emeka Nwanna - Academia.edu (original) (raw)

Papers by Emeka Nwanna

Research paper thumbnail of Green synthesis of CuNb<sub>2</sub>O<sub>6</sub> thin film using <i>allium cepa</i> as catalyst

Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, Apr 26, 2022

Research paper thumbnail of Facile Preparation and Characterization of Silica Nanoparticles from South Africa Fly Ash Using a Sol–Gel Hydrothermal Method

Processes, Nov 18, 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

Research paper thumbnail of The impact of CuO nanoparticles as fuel additives in biodiesel-blend fuelled diesel engine: A review

Energy & Environment, Apr 21, 2022

The utilization of fossil fuels like diesel has contributed immensely to ecological challenges su... more The utilization of fossil fuels like diesel has contributed immensely to ecological challenges such as the emission of greenhouse gasses. Hence, the motivation for sourcing another energy that is renewable as well as easily accessible from relatively cheap materials. Biodiesel is a perfect replacement for petro-diesel because it is biodegradable, economically viable, and has lower toxicity. However, there are challenges associated (poor engine efficiency) with its utilization in engines. It also raises NOx emissions which necessitates frequent engine component replacement owing to clogging, and it is ineffective in cold weather. To boost efficiency, nanoparticles can be combined with biodiesel blends. Moreover, the utilization of nanoparticle additives improves the performance of engines, rate of heat transfer, fuel mixture balance, thermo-physical characteristics, as well as the reduction in exhaust emissions. Copper oxide which is a transition metal oxide aids in the heat transfer from the engine down to the exhaust thus lowering the emissions of NOx. As a result, CuO nanoparticles are thought to have a lot of potential as a diesel engine additive and therefore, this review study was conducted to deduce the various techniques for generating CuO nano-fuels, the preparation methods, as well as their physicochemical features. Furthermore, the combustion behaviour, performance, and emission characteristics of diesel engines powered by CuO nanoparticle-containing biodiesel and blends were carefully investigated.

Research paper thumbnail of Biosynthesis and Fabrication of Copper Oxide Thin Films as a P-Type Semiconductor for Solar Cell Applications

Coatings, Dec 16, 2021

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

Research paper thumbnail of Synthesis and characterization of SnO2 thin films using metal organic precursors

Journal of King Saud University - Science, Jul 1, 2022

Research paper thumbnail of A numerical approach on the selection of the purge flow rate in an atomic layer deposition (ALD) process

Physics of Fluids

The variation of the purge flow rate is investigated in a reactor scale simulation of a typical a... more The variation of the purge flow rate is investigated in a reactor scale simulation of a typical atomic layer deposition (ALD) process. The investigation in its context addresses the possible issues of inadequate deposition rates with regard to the purge flow rate. A three-dimensional reactor is numerically implemented to simulate the physical and chemical processes to fabricate aluminum oxide (Al2O3) thin films. The purge flow rate disparity is focused to examine the effects within the fluid flow, mass transport, along with the chemical kinetics of the ALD process. The fabrication process employs trimethyl-aluminum and ozone (O3) as the metal and oxidant precursors, respectively, and inert argon as the purge gas. The reactor operation is set up to operate at a pressure of 10 torrs, with a substrate temperature of 200 °C. Three purge flow rates of 20, 10, and 5 sccm, respectively, have been examined. It was discovered that the slower flow rate showed, superior mass fraction distribut...

Research paper thumbnail of Investigation of the Acoustic Performance of Plantain (Musa Paradisiacal) Fibre Reinforced Epoxy Biocomposite

Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology

Sound is produced by the fluctuation of oscillation waves caused by variations in pressure in a m... more Sound is produced by the fluctuation of oscillation waves caused by variations in pressure in a medium containing various frequency ranges, which can be detected by either an animal or a human auditory apparatus and then transferred to the brain for analysis. Noise can be diminished and controlled by using absorptive materials. This is necessary because noise has a negative effect on public health, sharing of knowledge, and serenity, and it is getting worse every day as a result of urbanization and increased affiliated functions. Utilization of natural and synthetic reinforced polymer composites in noise pollution control is an emerging area of research. Natural fibers could potentially replace synthetic fibre reinforced composites due to their low impact on human health and environmental friendliness, according to research. Though academics have been excited about studying their mechanical features, little attention has been paid to quantifying their sound reduction behaviours. Nat...

Research paper thumbnail of Facile Preparation and Characterization of Silica Nanoparticles from South Africa Fly Ash Using a Sol–Gel Hydrothermal Method

Processes

Silica nanoparticles (SNPs) consist of several applications which include lightweight aggregates,... more Silica nanoparticles (SNPs) consist of several applications which include lightweight aggregates, energy storage, and drug delivery. Nevertheless, the silica reagents used in SNP synthesis are both costly and hazardous. As a result, it is critical to look for other sources of silica. For this research, a simple sol–gel hydrothermal approach is used to make SNPs from South African fly ash (SAFA). SAFA is classified as fly ash class F according to X-ray fluorescence (XRF) analysis. The wide-angle X-ray diffraction (XRD) pattern reveals the structural composition of SAFA and the amorphous phase of extracted SNPs, while Fourier transform infrared (FTIR) examination reveals the presence of silanol and siloxane groups. Basic SNPs were generally spherical with diameters of about 60 nm, according to scanning electron microscopy (SEM) and transition electron microscope (TEM) studies. The presence of SiO2 is confirmed by energy-dispersive X-ray spectroscopy (EDX) spectrum analysis. Particle s...

Research paper thumbnail of Synthesis and characterization of SnO2 thin films using metalorganic precursors

Journal of King Saud University - Science

Research paper thumbnail of Green synthesis of CuNb2O6 thin film using allium cepa as catalyst

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Research paper thumbnail of The impact of CuO nanoparticles as fuel additives in biodiesel-blend fuelled diesel engine: A review

Energy & Environment

The utilization of fossil fuels like diesel has contributed immensely to ecological challenges su... more The utilization of fossil fuels like diesel has contributed immensely to ecological challenges such as the emission of greenhouse gasses. Hence, the motivation for sourcing another energy that is renewable as well as easily accessible from relatively cheap materials. Biodiesel is a perfect replacement for petro-diesel because it is biodegradable, economically viable, and has lower toxicity. However, there are challenges associated (poor engine efficiency) with its utilization in engines. It also raises NOx emissions which necessitates frequent engine component replacement owing to clogging, and it is ineffective in cold weather. To boost efficiency, nanoparticles can be combined with biodiesel blends. Moreover, the utilization of nanoparticle additives improves the performance of engines, rate of heat transfer, fuel mixture balance, thermo-physical characteristics, as well as the reduction in exhaust emissions. Copper oxide which is a transition metal oxide aids in the heat transfer...

Research paper thumbnail of Synthesis of niobium pentoxide from bis(cyclopentadienyl) niobium(IV) dichloride using the spin coating process

Research paper thumbnail of Green synthesis preparation and evaluation of CuO doped SnO2

Journal of Materials Research and Technology, 2022

Research paper thumbnail of Biosynthesis and Fabrication of Copper Oxide Thin Films as a P-Type Semiconductor for Solar Cell Applications

Coatings, 2021

This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green syntheti... more This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green synthetic approach. A sol-gel spin coating technique was employed for the synthesis of the CuO thin film using Allium cepa as a reducing agent. The fabricated CuO thin film was investigated using the Fourier Transform-Infrared (FTIR) spectroscopy, Ultraviolet-visible spectra studies (UV-Vis), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and the Four-Point Probe measurement. The SEM micrographs revealed that the particles were spherically shaped, while the EDX analysis revealed that the CuO thin film was composed of copper and oxygen elements. Furthermore, the XRD analysis confirmed the monoclinic crystalline structure of the CuO thin film, while the FTIR spectroscopy investigated the chemical bonds formed during the production process. Contrarily, the UV-Vis spectroscopy reported a strong absorption of the film at the visible s...

Research paper thumbnail of Fabrication and synthesis of SnOX thin films: a review

The International Journal of Advanced Manufacturing Technology, 2020

Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and ... more Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and SnO 2), which is a functional material, has gained enormous attention for use in a variety of applications. Films of SnO X have a direct band gap between the ranges of 2.2 and 3.6 eV, with these films finding usefulness in various functions such as solar cells, transparent conducting oxides for gas sensors, lithium-ion batteries and microelectronics, and use in the optoelectronics industries. In order to satisfy the needs of a broad range of these applications, thin films with an extensive properties span defined by film composition, thickness, structural properties and morphology are required. This article explains the theory and research status of the various manufacturing processes of tin oxide. The purpose is to analyze the effects of the thin films through distinct forms of deposition. The general finding summarized in this research on SnO X showed that various researchers studied specific characteristics of tin oxide properties restricted by experimental conditions.

Research paper thumbnail of Investigating the Purge Flow Rate in a Reactor Scale Simulation of an Atomic Layer Deposition Process

Volume 2B: Advanced Manufacturing

This paper investigates the purge flow rate in a reactor scale simulation of an Atomic Layer Depo... more This paper investigates the purge flow rate in a reactor scale simulation of an Atomic Layer Deposition (ALD) process. A three-dimensional numerical analysis approach was implemented in the ALD process to fabricate thin films of aluminium oxide (Al2O3). Despite the abundance of literature on the specific use of, and increase in deposited material through the process of ALD, limited studies exist on the physical and chemical processes that occur during the growth of ALD. Previous literature has indicated that purging has presented a major challenge in the effective deposition rate of the ALD process. The precise purge flow rate has also been greatly contended. The importance of the purge sequence within the ALD process cannot be overemphasized. The term purge sequence refers to the essential property that defines the ALD advanced nano-fabrication technique in producing ultra-thin film. Therefore, this study focused on the purge flow rate effects of the ALD process. The reactants empl...

Research paper thumbnail of An overview of the application of atomic layer deposition process for lithium‐ion based batteries

International Journal of Energy Research

Research paper thumbnail of Green synthesis of CuNb<sub>2</sub>O<sub>6</sub> thin film using <i>allium cepa</i> as catalyst

Energy Sources, Part A: Recovery, Utilization, And Environmental Effects, Apr 26, 2022

Research paper thumbnail of Facile Preparation and Characterization of Silica Nanoparticles from South Africa Fly Ash Using a Sol–Gel Hydrothermal Method

Processes, Nov 18, 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

Research paper thumbnail of The impact of CuO nanoparticles as fuel additives in biodiesel-blend fuelled diesel engine: A review

Energy & Environment, Apr 21, 2022

The utilization of fossil fuels like diesel has contributed immensely to ecological challenges su... more The utilization of fossil fuels like diesel has contributed immensely to ecological challenges such as the emission of greenhouse gasses. Hence, the motivation for sourcing another energy that is renewable as well as easily accessible from relatively cheap materials. Biodiesel is a perfect replacement for petro-diesel because it is biodegradable, economically viable, and has lower toxicity. However, there are challenges associated (poor engine efficiency) with its utilization in engines. It also raises NOx emissions which necessitates frequent engine component replacement owing to clogging, and it is ineffective in cold weather. To boost efficiency, nanoparticles can be combined with biodiesel blends. Moreover, the utilization of nanoparticle additives improves the performance of engines, rate of heat transfer, fuel mixture balance, thermo-physical characteristics, as well as the reduction in exhaust emissions. Copper oxide which is a transition metal oxide aids in the heat transfer from the engine down to the exhaust thus lowering the emissions of NOx. As a result, CuO nanoparticles are thought to have a lot of potential as a diesel engine additive and therefore, this review study was conducted to deduce the various techniques for generating CuO nano-fuels, the preparation methods, as well as their physicochemical features. Furthermore, the combustion behaviour, performance, and emission characteristics of diesel engines powered by CuO nanoparticle-containing biodiesel and blends were carefully investigated.

Research paper thumbnail of Biosynthesis and Fabrication of Copper Oxide Thin Films as a P-Type Semiconductor for Solar Cell Applications

Coatings, Dec 16, 2021

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

Research paper thumbnail of Synthesis and characterization of SnO2 thin films using metal organic precursors

Journal of King Saud University - Science, Jul 1, 2022

Research paper thumbnail of A numerical approach on the selection of the purge flow rate in an atomic layer deposition (ALD) process

Physics of Fluids

The variation of the purge flow rate is investigated in a reactor scale simulation of a typical a... more The variation of the purge flow rate is investigated in a reactor scale simulation of a typical atomic layer deposition (ALD) process. The investigation in its context addresses the possible issues of inadequate deposition rates with regard to the purge flow rate. A three-dimensional reactor is numerically implemented to simulate the physical and chemical processes to fabricate aluminum oxide (Al2O3) thin films. The purge flow rate disparity is focused to examine the effects within the fluid flow, mass transport, along with the chemical kinetics of the ALD process. The fabrication process employs trimethyl-aluminum and ozone (O3) as the metal and oxidant precursors, respectively, and inert argon as the purge gas. The reactor operation is set up to operate at a pressure of 10 torrs, with a substrate temperature of 200 °C. Three purge flow rates of 20, 10, and 5 sccm, respectively, have been examined. It was discovered that the slower flow rate showed, superior mass fraction distribut...

Research paper thumbnail of Investigation of the Acoustic Performance of Plantain (Musa Paradisiacal) Fibre Reinforced Epoxy Biocomposite

Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advances in Aerospace Technology

Sound is produced by the fluctuation of oscillation waves caused by variations in pressure in a m... more Sound is produced by the fluctuation of oscillation waves caused by variations in pressure in a medium containing various frequency ranges, which can be detected by either an animal or a human auditory apparatus and then transferred to the brain for analysis. Noise can be diminished and controlled by using absorptive materials. This is necessary because noise has a negative effect on public health, sharing of knowledge, and serenity, and it is getting worse every day as a result of urbanization and increased affiliated functions. Utilization of natural and synthetic reinforced polymer composites in noise pollution control is an emerging area of research. Natural fibers could potentially replace synthetic fibre reinforced composites due to their low impact on human health and environmental friendliness, according to research. Though academics have been excited about studying their mechanical features, little attention has been paid to quantifying their sound reduction behaviours. Nat...

Research paper thumbnail of Facile Preparation and Characterization of Silica Nanoparticles from South Africa Fly Ash Using a Sol–Gel Hydrothermal Method

Processes

Silica nanoparticles (SNPs) consist of several applications which include lightweight aggregates,... more Silica nanoparticles (SNPs) consist of several applications which include lightweight aggregates, energy storage, and drug delivery. Nevertheless, the silica reagents used in SNP synthesis are both costly and hazardous. As a result, it is critical to look for other sources of silica. For this research, a simple sol–gel hydrothermal approach is used to make SNPs from South African fly ash (SAFA). SAFA is classified as fly ash class F according to X-ray fluorescence (XRF) analysis. The wide-angle X-ray diffraction (XRD) pattern reveals the structural composition of SAFA and the amorphous phase of extracted SNPs, while Fourier transform infrared (FTIR) examination reveals the presence of silanol and siloxane groups. Basic SNPs were generally spherical with diameters of about 60 nm, according to scanning electron microscopy (SEM) and transition electron microscope (TEM) studies. The presence of SiO2 is confirmed by energy-dispersive X-ray spectroscopy (EDX) spectrum analysis. Particle s...

Research paper thumbnail of Synthesis and characterization of SnO2 thin films using metalorganic precursors

Journal of King Saud University - Science

Research paper thumbnail of Green synthesis of CuNb2O6 thin film using allium cepa as catalyst

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects

Research paper thumbnail of The impact of CuO nanoparticles as fuel additives in biodiesel-blend fuelled diesel engine: A review

Energy & Environment

The utilization of fossil fuels like diesel has contributed immensely to ecological challenges su... more The utilization of fossil fuels like diesel has contributed immensely to ecological challenges such as the emission of greenhouse gasses. Hence, the motivation for sourcing another energy that is renewable as well as easily accessible from relatively cheap materials. Biodiesel is a perfect replacement for petro-diesel because it is biodegradable, economically viable, and has lower toxicity. However, there are challenges associated (poor engine efficiency) with its utilization in engines. It also raises NOx emissions which necessitates frequent engine component replacement owing to clogging, and it is ineffective in cold weather. To boost efficiency, nanoparticles can be combined with biodiesel blends. Moreover, the utilization of nanoparticle additives improves the performance of engines, rate of heat transfer, fuel mixture balance, thermo-physical characteristics, as well as the reduction in exhaust emissions. Copper oxide which is a transition metal oxide aids in the heat transfer...

Research paper thumbnail of Synthesis of niobium pentoxide from bis(cyclopentadienyl) niobium(IV) dichloride using the spin coating process

Research paper thumbnail of Green synthesis preparation and evaluation of CuO doped SnO2

Journal of Materials Research and Technology, 2022

Research paper thumbnail of Biosynthesis and Fabrication of Copper Oxide Thin Films as a P-Type Semiconductor for Solar Cell Applications

Coatings, 2021

This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green syntheti... more This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green synthetic approach. A sol-gel spin coating technique was employed for the synthesis of the CuO thin film using Allium cepa as a reducing agent. The fabricated CuO thin film was investigated using the Fourier Transform-Infrared (FTIR) spectroscopy, Ultraviolet-visible spectra studies (UV-Vis), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and the Four-Point Probe measurement. The SEM micrographs revealed that the particles were spherically shaped, while the EDX analysis revealed that the CuO thin film was composed of copper and oxygen elements. Furthermore, the XRD analysis confirmed the monoclinic crystalline structure of the CuO thin film, while the FTIR spectroscopy investigated the chemical bonds formed during the production process. Contrarily, the UV-Vis spectroscopy reported a strong absorption of the film at the visible s...

Research paper thumbnail of Fabrication and synthesis of SnOX thin films: a review

The International Journal of Advanced Manufacturing Technology, 2020

Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and ... more Due to its exceptional electrical, optical, chemical and magnetic properties, tin oxide (SnO and SnO 2), which is a functional material, has gained enormous attention for use in a variety of applications. Films of SnO X have a direct band gap between the ranges of 2.2 and 3.6 eV, with these films finding usefulness in various functions such as solar cells, transparent conducting oxides for gas sensors, lithium-ion batteries and microelectronics, and use in the optoelectronics industries. In order to satisfy the needs of a broad range of these applications, thin films with an extensive properties span defined by film composition, thickness, structural properties and morphology are required. This article explains the theory and research status of the various manufacturing processes of tin oxide. The purpose is to analyze the effects of the thin films through distinct forms of deposition. The general finding summarized in this research on SnO X showed that various researchers studied specific characteristics of tin oxide properties restricted by experimental conditions.

Research paper thumbnail of Investigating the Purge Flow Rate in a Reactor Scale Simulation of an Atomic Layer Deposition Process

Volume 2B: Advanced Manufacturing

This paper investigates the purge flow rate in a reactor scale simulation of an Atomic Layer Depo... more This paper investigates the purge flow rate in a reactor scale simulation of an Atomic Layer Deposition (ALD) process. A three-dimensional numerical analysis approach was implemented in the ALD process to fabricate thin films of aluminium oxide (Al2O3). Despite the abundance of literature on the specific use of, and increase in deposited material through the process of ALD, limited studies exist on the physical and chemical processes that occur during the growth of ALD. Previous literature has indicated that purging has presented a major challenge in the effective deposition rate of the ALD process. The precise purge flow rate has also been greatly contended. The importance of the purge sequence within the ALD process cannot be overemphasized. The term purge sequence refers to the essential property that defines the ALD advanced nano-fabrication technique in producing ultra-thin film. Therefore, this study focused on the purge flow rate effects of the ALD process. The reactants empl...

Research paper thumbnail of An overview of the application of atomic layer deposition process for lithium‐ion based batteries

International Journal of Energy Research