An electrochemical urea biosensor on a carbon nanofiber-poly (amidoamine) dendrimer supramolecular-platform
- Authors: Blessie, Wessel
- Date: 2020
- Subjects: Supramolecular electrochemistry , Nanomedicine , Polymeric composites , Carbon composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/473889 , uj:42696
- Description: Abstract: The concentration of urea in serum or urine in human body should be in moderate levels (3.3–6.7 mM). The elevation of urea above the normal level indicates gastrointestinal bleeding, obstruction of the urinary tract, burns, shock, or renal failure. The decline in the concentration of urea below moderate levels causes cachexia, hepatic failure, and nephritic syndrome. The increase/decrease in the concentration of urea poses health risks. Thus, it is essential to determine the urea concentration for early diagnosis of kidney related disease. In this mini-dissertation, we report a novel amperometric urea biosensor based on the immobilisation of urease enzyme on carbon nanofiber-generation 3 polyamidoamine dendrimer immobilisation layer on a glassy carbon electrode (GCE). Electrospun polyacrylonitrile (PAN) based carbon nanofibers were obtained with an average diameter of 132 nm through stabilization, electrospinning, and carbonization of polyacrylonitrile (PAN) polymer. The structure and the morphology of the PAN carbon nanofibers were studied by High Resolution Transmission Electron Microscope (HR-TEM) and Field Emission Scanning Electron Microscope (FE-SEM)... , M.Sc. (Nanoscience)
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- Authors: Blessie, Wessel
- Date: 2020
- Subjects: Supramolecular electrochemistry , Nanomedicine , Polymeric composites , Carbon composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/473889 , uj:42696
- Description: Abstract: The concentration of urea in serum or urine in human body should be in moderate levels (3.3–6.7 mM). The elevation of urea above the normal level indicates gastrointestinal bleeding, obstruction of the urinary tract, burns, shock, or renal failure. The decline in the concentration of urea below moderate levels causes cachexia, hepatic failure, and nephritic syndrome. The increase/decrease in the concentration of urea poses health risks. Thus, it is essential to determine the urea concentration for early diagnosis of kidney related disease. In this mini-dissertation, we report a novel amperometric urea biosensor based on the immobilisation of urease enzyme on carbon nanofiber-generation 3 polyamidoamine dendrimer immobilisation layer on a glassy carbon electrode (GCE). Electrospun polyacrylonitrile (PAN) based carbon nanofibers were obtained with an average diameter of 132 nm through stabilization, electrospinning, and carbonization of polyacrylonitrile (PAN) polymer. The structure and the morphology of the PAN carbon nanofibers were studied by High Resolution Transmission Electron Microscope (HR-TEM) and Field Emission Scanning Electron Microscope (FE-SEM)... , M.Sc. (Nanoscience)
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Dispersion characteristics and effect of heating rates on the mechanical properties of spark plasma sintered multi-walled carbon nanotubes reinforced nickel aluminide composites
- Authors: Ayodele, Olusoji Oluremi
- Date: 2020
- Subjects: Carbon nanotubes , Nickel-aluminum alloys , Carbon composites
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/481841 , uj:43673
- Description: D.Phil. , Abstract: The dispersion of multi-walled carbon nanotubes (MWCNTs) in NiAl matrix was successfully carried out through the combination of two steps planetary ball millings. Low energy ball milling (LEBM) was employed for preliminary milling of the starting powders at 150 rpm. Subsequently, the milled powders were transferred to the high energy ball milling (HEBM) for auxiliary milling, and to ensure proper dispersion. This was performed at different milling hours (1 h, 2 h and 3 h) to further de-bundle the MWCNTs. The milled powders were consolidated via spark plasma sintering (SPS) using the sintering temperature of 1000 oC, sintering pressure of 50 MPa, holding time of 10 min and heating rates from 50-150 oC/min. The morphology of the milled powders and the consolidated compacts were observed using the scanning electron microscopy (SEM) and the structural and phase identifications were examined through the X-ray diffractometer (XRD). Raman spectroscopy was used to determine the structural integrity of MWCNTs in the metal matrix and Transmission electron microscopy (TEM) revealed the level of damages or defects done to the MWCNTs. The SEM micrograph of the consolidated NiAl-1wt% MWCNTs composite (HEBM, 1 hour) revealed a relative dispersion of MWCNTs with a few agglomerations and this was corroborated by the TEM images. Furthermore, the Vickers microhardness and relative density of the consolidated samples was observed to decrease as the heating rate was increased and further increase in heating rate led to the increase in the density of the consolidated NiAl. Conversely, the Vickers microhardness and relative density of the consolidated NiAl-1wt% MWCNTs composites decreased as the heating rate was increased from 50-150 oC/min. The nanoindentation plot indicates that the sintered samples with higher penetration depths at the indentation load of 75 mN had lower nanohardness values. MWCNTs was observed to have decreased the coefficient of friction due to the formation of lubricating tribolayer at the contact...
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- Authors: Ayodele, Olusoji Oluremi
- Date: 2020
- Subjects: Carbon nanotubes , Nickel-aluminum alloys , Carbon composites
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/481841 , uj:43673
- Description: D.Phil. , Abstract: The dispersion of multi-walled carbon nanotubes (MWCNTs) in NiAl matrix was successfully carried out through the combination of two steps planetary ball millings. Low energy ball milling (LEBM) was employed for preliminary milling of the starting powders at 150 rpm. Subsequently, the milled powders were transferred to the high energy ball milling (HEBM) for auxiliary milling, and to ensure proper dispersion. This was performed at different milling hours (1 h, 2 h and 3 h) to further de-bundle the MWCNTs. The milled powders were consolidated via spark plasma sintering (SPS) using the sintering temperature of 1000 oC, sintering pressure of 50 MPa, holding time of 10 min and heating rates from 50-150 oC/min. The morphology of the milled powders and the consolidated compacts were observed using the scanning electron microscopy (SEM) and the structural and phase identifications were examined through the X-ray diffractometer (XRD). Raman spectroscopy was used to determine the structural integrity of MWCNTs in the metal matrix and Transmission electron microscopy (TEM) revealed the level of damages or defects done to the MWCNTs. The SEM micrograph of the consolidated NiAl-1wt% MWCNTs composite (HEBM, 1 hour) revealed a relative dispersion of MWCNTs with a few agglomerations and this was corroborated by the TEM images. Furthermore, the Vickers microhardness and relative density of the consolidated samples was observed to decrease as the heating rate was increased and further increase in heating rate led to the increase in the density of the consolidated NiAl. Conversely, the Vickers microhardness and relative density of the consolidated NiAl-1wt% MWCNTs composites decreased as the heating rate was increased from 50-150 oC/min. The nanoindentation plot indicates that the sintered samples with higher penetration depths at the indentation load of 75 mN had lower nanohardness values. MWCNTs was observed to have decreased the coefficient of friction due to the formation of lubricating tribolayer at the contact...
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Microstructural characterization and mechanical properties of carbon nanotube reinforced nickel aluminide composites
- Authors: Awotunde, Mary Ajimegoh
- Date: 2020
- Subjects: Nickel - Aluminum alloys , Diffusion - Defects , Nanotubes - Carbon content , Fracture mechanics , Carbon composites
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/413118 , uj:34791
- Description: Ph.D. (Metallurgy) , Abstract: Toughened nickel aluminides were successfully synthesized by incorporating multi-walled carbon nanotubes (MWCNTs) into nickel aluminide (NiAl) intermetallic matrix. The drive to retain the relative lightweight of NiAl motivated the choice of MWCNTs as the reinforcing agent in this study. Moreover, enhanced mechanical properties were anticipated in the reinforced composites owing to the exceptional properties of the MWCNTs. Elemental powders of nickel and aluminium were blended together with MWCNTs in a novel two stage ball milling for optimum dispersion and preservation of the structural integrity of the MWCNTs. The milled powders were consolidated by Spark Plasma Sintering (model HHPD- 25, FCT GmbH, Germany). The milled powders and sintered samples were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy and X-Ray Diffraction. The nano-structural evolution of the MWCNTs during their dispersion via dry ball milling was further evaluated using Raman Spectroscopy. The mechanical properties and fracture behaviours of the reinforced sintered samples were critically evaluated using nanoindentation techniques. Results show that the integration of MWCNTs into the NiAl matrix led to an enhancement of the fracture toughness. An inverse relationship between the hardness and fracture toughness of the NiAl composites was established. The intergranular fracture morphology of the unreinforced NiAl transited to a dominantly dimpled fracture morphology in the NiAl-1.0 wt% CNTs composites indicating enhanced ductility and fracture toughness. The improvement of the fracture toughness of the reinforced NiAl is attributed to the uniform dispersion of theMWCNTs within the NiAl matrix, the preservation ofMWCNTs aspect ratios and the disordering of the B2 ordered NiAl intermetallic structure.
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- Authors: Awotunde, Mary Ajimegoh
- Date: 2020
- Subjects: Nickel - Aluminum alloys , Diffusion - Defects , Nanotubes - Carbon content , Fracture mechanics , Carbon composites
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/413118 , uj:34791
- Description: Ph.D. (Metallurgy) , Abstract: Toughened nickel aluminides were successfully synthesized by incorporating multi-walled carbon nanotubes (MWCNTs) into nickel aluminide (NiAl) intermetallic matrix. The drive to retain the relative lightweight of NiAl motivated the choice of MWCNTs as the reinforcing agent in this study. Moreover, enhanced mechanical properties were anticipated in the reinforced composites owing to the exceptional properties of the MWCNTs. Elemental powders of nickel and aluminium were blended together with MWCNTs in a novel two stage ball milling for optimum dispersion and preservation of the structural integrity of the MWCNTs. The milled powders were consolidated by Spark Plasma Sintering (model HHPD- 25, FCT GmbH, Germany). The milled powders and sintered samples were characterized using Scanning Electron Microscopy, Transmission Electron Microscopy and X-Ray Diffraction. The nano-structural evolution of the MWCNTs during their dispersion via dry ball milling was further evaluated using Raman Spectroscopy. The mechanical properties and fracture behaviours of the reinforced sintered samples were critically evaluated using nanoindentation techniques. Results show that the integration of MWCNTs into the NiAl matrix led to an enhancement of the fracture toughness. An inverse relationship between the hardness and fracture toughness of the NiAl composites was established. The intergranular fracture morphology of the unreinforced NiAl transited to a dominantly dimpled fracture morphology in the NiAl-1.0 wt% CNTs composites indicating enhanced ductility and fracture toughness. The improvement of the fracture toughness of the reinforced NiAl is attributed to the uniform dispersion of theMWCNTs within the NiAl matrix, the preservation ofMWCNTs aspect ratios and the disordering of the B2 ordered NiAl intermetallic structure.
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Synthesis and modifications of polymer-based carbon/metal organic framework composites for hydrogen storage applications
- Authors: Molefe, Lerato
- Date: 2019
- Subjects: Polymeric composites , Carbon nanotubes , Carbon composites , Nanocomposites (Materials)
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/417836 , uj:35402
- Description: Abstract: The South African energy landscape is dominated by carbon dioxide (CO2) emitting coal combustion which is currently plentiful and cheap however because of its finite nature, it will soon diminish. With the current growing population and increasing energy need, research scientists all over the world are continuously working towards shifting to cleaner renewable energy sources of which hydrogen (H2) is a promising candidate. Hydrogen has a high gravimetric energy density than any other fuel and its combustion in pure oxygen only produces water vapour and heat. However, since it is very light and as a result has a low volumetric energy density, its storage is very difficult. Generally, adsorbents materials such as metal-organic frameworks (MOFs) such as Materials Institute Lavoisier (MIL-101(Cr)) and Universitetet i Oslo (UiO-66(Zr)) as well as porous carbons such as zeolite templated carbon (ZTC) have been well investigated for H2 storage due to their unique properties such as extremely high surface areas and ultrahigh porosities. However, their great potential in H2 storage applications is limited by their lack of immediate processability, because they are obtained as fine powders in their as-synthesised form. For these materials to gain practical applications in H2 storage they must be shaped into mechanically stable and easy to handle bodies like monoliths. The process of shaping MOFs and carbon powders often includes the use of various non-porous polymers and inorganic materials as binders and that often results in pore-blocking effects and low H2 uptake... , Ph.D. (Chemistry)
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- Authors: Molefe, Lerato
- Date: 2019
- Subjects: Polymeric composites , Carbon nanotubes , Carbon composites , Nanocomposites (Materials)
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/417836 , uj:35402
- Description: Abstract: The South African energy landscape is dominated by carbon dioxide (CO2) emitting coal combustion which is currently plentiful and cheap however because of its finite nature, it will soon diminish. With the current growing population and increasing energy need, research scientists all over the world are continuously working towards shifting to cleaner renewable energy sources of which hydrogen (H2) is a promising candidate. Hydrogen has a high gravimetric energy density than any other fuel and its combustion in pure oxygen only produces water vapour and heat. However, since it is very light and as a result has a low volumetric energy density, its storage is very difficult. Generally, adsorbents materials such as metal-organic frameworks (MOFs) such as Materials Institute Lavoisier (MIL-101(Cr)) and Universitetet i Oslo (UiO-66(Zr)) as well as porous carbons such as zeolite templated carbon (ZTC) have been well investigated for H2 storage due to their unique properties such as extremely high surface areas and ultrahigh porosities. However, their great potential in H2 storage applications is limited by their lack of immediate processability, because they are obtained as fine powders in their as-synthesised form. For these materials to gain practical applications in H2 storage they must be shaped into mechanically stable and easy to handle bodies like monoliths. The process of shaping MOFs and carbon powders often includes the use of various non-porous polymers and inorganic materials as binders and that often results in pore-blocking effects and low H2 uptake... , Ph.D. (Chemistry)
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Synthesis and characterization of polymer and carbonaceous nanocomposites and their application in hydrostatic pressure sensing
- Authors: Mofokeng, Lethula Excellent
- Date: 2017
- Subjects: Carbon composites , Nanocomposites (Materials) , Nanostructured materials , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/244052 , uj:25235
- Description: M.Sc. (Nanoscience) , Abstract: Flexible polymer nanocomposites thin films holds promising applications in electronics and are good candidates for pressure sensing and other technological applications due to their flexibility and other novel properties they exhibits. Carbonaceous nanomaterial polymer nanocomposites were utilized to fabricate pressure sensors via a simple and cost- effective process of non-covalent functionalization. We successfully managed to demonstrate the use of cheap, stable, thermoplastic polymers for producing thin films for pressure sensing applications and applicable also for future electronic devices applications. The use of CNPs gave better resistive and capacitive sensing application with response times ranging from 3 to 11 seconds and operate effective for a wide dynamic range (56 to 190 kPa) for both resistive and capacitive sensing compared to O-MWCNTs. The sensitivities of carbonaceous nanomaterials are dependent on the nature of the polymer, loadings of polymer ratios (1:1, 1:2, 1:3, 2:1, 2:2, 2:3, 3:1, 3:2 and 3:3) and percolation threshold. CNPs/PAN pressure sensor was measured for electrical resistance and capacitance pressure sensing. The CNPs/PAN was the highest sensitivity resistive pressure sensor than any other in relation to O-MWCNTs and rGO – based pressure sensors having 5.12 kPa-1. CNPs/PAN took three second to reach 90% pressure stimuli response time and also it took in three seconds for 90 % recovery time to retain its initial state at Ro under applied pressure with linear range from 56 to 190 kPa. Capacitive sensitivity was 1.33 kPa-1 for CNPs and CA thin film pressure sensor exhibiting linearity with a wide dynamic range and reversible behaviour. When Fe3O4 was incorporated to CNPs and CA, low sensitivities for resistive and capacitive pressure sensing were obtained for CNPs/Fe3O4/CA. Resistive sensitivity was 2.08 x 10-6 kPa-1 and 0.04 kPa-1 for capacitive sensitivities. This implies that, Fe3O4 had a huge impact on the structure, arrangement, uniformity, distribution and conducting channels within the polymer nanocomposites. As for O-MWCNTs and rGO –based pressure sensors, similar reduction in sensitivities due to Fe3O4...
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- Authors: Mofokeng, Lethula Excellent
- Date: 2017
- Subjects: Carbon composites , Nanocomposites (Materials) , Nanostructured materials , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/244052 , uj:25235
- Description: M.Sc. (Nanoscience) , Abstract: Flexible polymer nanocomposites thin films holds promising applications in electronics and are good candidates for pressure sensing and other technological applications due to their flexibility and other novel properties they exhibits. Carbonaceous nanomaterial polymer nanocomposites were utilized to fabricate pressure sensors via a simple and cost- effective process of non-covalent functionalization. We successfully managed to demonstrate the use of cheap, stable, thermoplastic polymers for producing thin films for pressure sensing applications and applicable also for future electronic devices applications. The use of CNPs gave better resistive and capacitive sensing application with response times ranging from 3 to 11 seconds and operate effective for a wide dynamic range (56 to 190 kPa) for both resistive and capacitive sensing compared to O-MWCNTs. The sensitivities of carbonaceous nanomaterials are dependent on the nature of the polymer, loadings of polymer ratios (1:1, 1:2, 1:3, 2:1, 2:2, 2:3, 3:1, 3:2 and 3:3) and percolation threshold. CNPs/PAN pressure sensor was measured for electrical resistance and capacitance pressure sensing. The CNPs/PAN was the highest sensitivity resistive pressure sensor than any other in relation to O-MWCNTs and rGO – based pressure sensors having 5.12 kPa-1. CNPs/PAN took three second to reach 90% pressure stimuli response time and also it took in three seconds for 90 % recovery time to retain its initial state at Ro under applied pressure with linear range from 56 to 190 kPa. Capacitive sensitivity was 1.33 kPa-1 for CNPs and CA thin film pressure sensor exhibiting linearity with a wide dynamic range and reversible behaviour. When Fe3O4 was incorporated to CNPs and CA, low sensitivities for resistive and capacitive pressure sensing were obtained for CNPs/Fe3O4/CA. Resistive sensitivity was 2.08 x 10-6 kPa-1 and 0.04 kPa-1 for capacitive sensitivities. This implies that, Fe3O4 had a huge impact on the structure, arrangement, uniformity, distribution and conducting channels within the polymer nanocomposites. As for O-MWCNTs and rGO –based pressure sensors, similar reduction in sensitivities due to Fe3O4...
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Electrochemical detection of arsenic and selenium on modified carbon based nanocomposite electrodes
- Authors: Idris, Azeez Olayiwola
- Date: 2016
- Subjects: Nanostructured materials , Electrodes, Carbon , Electrochemical analysis , Organic water pollutants , Carbon composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124946 , uj:20978
- Description: Abstract: This study explores the applications of nanomaterial modified on glassy carbon electrode (GCE) in the electroanalysis of arsenic and selenium ions in water. GCE was modified with gold nanoparticles and reduced graphene oxide. Gold nanoparticle (AuNPs) modified GCE (GCE-AuNPs) was prepared by electrochemical deposition of gold from 5 mM of HAuCl4 solutions by cycling the potential from -400 mV to 1100 mV for 10 cycles at a scan rate of 50 mVs-1. GCEAuNPs was electrochemically investigated using redox probes which are [Fe (CN) 6]3-/4- and Ru (NH3)62+/3+. The current and the reversibility of the redox probes were enhanced in the presence of modifiers. The electrochemical determination of selenium by square wave anodic stripping voltammetry (SWASV) using GCE-AuNPs was carried out under the optimised conditions: pH 1, deposition potential of -100 mV, deposition time of 60 s and 0.1 M H2SO4 as supporting electrolyte. A detection limit of 0.64 μg L-1 was obtained. Cu and Cd were the only significant interferences observed for the electrochemical detection of selenium. Attempt was also made to sense selenium in tap water, concentration of 8.86 (± 0.34) ppb Se, was calculated for the tap water. The electrochemical method was validated with ICP-OES. Furthermore, arsenic was detected on GCE-AuNPs by SWASV. The sensing of arsenic was also optimised at different analytical conditions and a detection limit of 0.75 μgL-1 was obtained. Cu, Cd and Hg were the major interferences in arsenic sensing. Ammonia, EDTA and G3 PPI were used as ligands to mask the interference effect of copper on arsenic sensing in the bid to remove interference. Graphene oxide was synthesised by using Hummer`s methods and was further reduced to reduced graphene oxide using ascorbic acid. The reduced graphene oxide was used to modify GCE, the modification of GCE with rGO-GCE resulted in an increase in the electroactive surface area of the electrode which led to enhance the redox peak of [Fe(CN)6]3-/4- in comparison to the bare GCE. SWASV was used to detect Se (IV) in water at the following optimum conditions: 0.1 M HNO3 as supporting electrolyte, deposition potential of -100 mV and pre-concentration time of 240 s. The rGO-GCE sensor was able to detect Se (IV) to the limit of 2.2 ppb and was not susceptible to many interfering cations except Cu (II) and Cd (II). , M.Sc. (Chemistry)
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- Authors: Idris, Azeez Olayiwola
- Date: 2016
- Subjects: Nanostructured materials , Electrodes, Carbon , Electrochemical analysis , Organic water pollutants , Carbon composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124946 , uj:20978
- Description: Abstract: This study explores the applications of nanomaterial modified on glassy carbon electrode (GCE) in the electroanalysis of arsenic and selenium ions in water. GCE was modified with gold nanoparticles and reduced graphene oxide. Gold nanoparticle (AuNPs) modified GCE (GCE-AuNPs) was prepared by electrochemical deposition of gold from 5 mM of HAuCl4 solutions by cycling the potential from -400 mV to 1100 mV for 10 cycles at a scan rate of 50 mVs-1. GCEAuNPs was electrochemically investigated using redox probes which are [Fe (CN) 6]3-/4- and Ru (NH3)62+/3+. The current and the reversibility of the redox probes were enhanced in the presence of modifiers. The electrochemical determination of selenium by square wave anodic stripping voltammetry (SWASV) using GCE-AuNPs was carried out under the optimised conditions: pH 1, deposition potential of -100 mV, deposition time of 60 s and 0.1 M H2SO4 as supporting electrolyte. A detection limit of 0.64 μg L-1 was obtained. Cu and Cd were the only significant interferences observed for the electrochemical detection of selenium. Attempt was also made to sense selenium in tap water, concentration of 8.86 (± 0.34) ppb Se, was calculated for the tap water. The electrochemical method was validated with ICP-OES. Furthermore, arsenic was detected on GCE-AuNPs by SWASV. The sensing of arsenic was also optimised at different analytical conditions and a detection limit of 0.75 μgL-1 was obtained. Cu, Cd and Hg were the major interferences in arsenic sensing. Ammonia, EDTA and G3 PPI were used as ligands to mask the interference effect of copper on arsenic sensing in the bid to remove interference. Graphene oxide was synthesised by using Hummer`s methods and was further reduced to reduced graphene oxide using ascorbic acid. The reduced graphene oxide was used to modify GCE, the modification of GCE with rGO-GCE resulted in an increase in the electroactive surface area of the electrode which led to enhance the redox peak of [Fe(CN)6]3-/4- in comparison to the bare GCE. SWASV was used to detect Se (IV) in water at the following optimum conditions: 0.1 M HNO3 as supporting electrolyte, deposition potential of -100 mV and pre-concentration time of 240 s. The rGO-GCE sensor was able to detect Se (IV) to the limit of 2.2 ppb and was not susceptible to many interfering cations except Cu (II) and Cd (II). , M.Sc. (Chemistry)
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Development of advanced carbon based composite electrodes for the detection and the degradation of organic pollutants in water via electrochemical/photoelectrochemical processes
- Authors: Ntsendwana, Bulelwa
- Date: 2014-07-15
- Subjects: Carbon composites , Electrodes, Carbon , Organic water pollutants , Electrochemical analysis , Photoelectrochemistry
- Type: Thesis
- Identifier: uj:11656 , http://hdl.handle.net/10210/11379
- Description: Ph.D. (Chemistry) , In this study, carbon based electrode materials such as glassy carbon, graphene, diamond and exfoliated graphite were explored as suitable electrode materials for electrochemical detection, electrochemical and photoelectrochemical degradation of organic water pollutants. Graphene modified glassy carbon electrode sensor was developed for bisphenol A. Cyclic voltammetry was used to study the electrochemical properties of the prepared graphene- modified glassy carbon electrode using potassium ferricyanide as a redox probe. The prepared graphene- modified glassy carbon electrode exhibited more facile electron kinetics and enhanced current of about 75% when compared to the unmodified glassy carbon electrode...
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- Authors: Ntsendwana, Bulelwa
- Date: 2014-07-15
- Subjects: Carbon composites , Electrodes, Carbon , Organic water pollutants , Electrochemical analysis , Photoelectrochemistry
- Type: Thesis
- Identifier: uj:11656 , http://hdl.handle.net/10210/11379
- Description: Ph.D. (Chemistry) , In this study, carbon based electrode materials such as glassy carbon, graphene, diamond and exfoliated graphite were explored as suitable electrode materials for electrochemical detection, electrochemical and photoelectrochemical degradation of organic water pollutants. Graphene modified glassy carbon electrode sensor was developed for bisphenol A. Cyclic voltammetry was used to study the electrochemical properties of the prepared graphene- modified glassy carbon electrode using potassium ferricyanide as a redox probe. The prepared graphene- modified glassy carbon electrode exhibited more facile electron kinetics and enhanced current of about 75% when compared to the unmodified glassy carbon electrode...
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Towards the synthesis of doped carbon nanotube/polysulfone nanofiltration membranes for the removal of organic pollutants from water
- Authors: Yokwana, Kholiswa
- Date: 2014-06-26
- Subjects: Organic water pollutants , Carbon composites , Nanostructured materials , Nanotubes
- Type: Thesis
- Identifier: uj:11603 , http://hdl.handle.net/10210/11315
- Description: M.Tech. (Chemistry) , Please refer to full text to view abstract
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- Authors: Yokwana, Kholiswa
- Date: 2014-06-26
- Subjects: Organic water pollutants , Carbon composites , Nanostructured materials , Nanotubes
- Type: Thesis
- Identifier: uj:11603 , http://hdl.handle.net/10210/11315
- Description: M.Tech. (Chemistry) , Please refer to full text to view abstract
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