SHARIFAH BEE ABD HAMID - Academia.edu (original) (raw)
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Papers by SHARIFAH BEE ABD HAMID
In this paper, a facile electrodeposition synthesis was introduced to prepare the nanodisk-dendri... more In this paper, a facile electrodeposition synthesis was introduced to prepare the nanodisk-dendritic ZnO film using a mixture solution of zinc chloride (ZnCl2) with potassium chloride (KCl) acted as a directing agent. This study aims to determine the best photoelectrochemical response for solar-induced water splitting. Based on our results obtained, it was found that an average diagonal of nanodisk was approximately 1.70 µm with the thickness of ≈ 150 nm in thickness was successfully grown on the surface of substrate. The photocatalytic and photoelectrochemical response of the resultant wurtzite type based - nanodisk-dendrite ZnO film as compared to the as-prepared ZnO film were monitored and evaluated. A photocurrent density of 19.87 mA/cm2 under ultraviolet rays and 14.05 mA/cm2 under visible light (500nm) was recorded for the newly developed nanodisk-dendritic ZnO thin film. It was believed that nanodisk-dendritic ZnO film can harvest more incident photons from the illumination to generate more photo-induced charge carriers to trigger the photocatalytic and photoelectrochemical reactions. Moreover, strong light scattering effects and high specific surface area of 2D-nanostructures aid for the incident light absorption from any direction.
High aspect ratio of WO3-loaded TiO2 nanotube arrays have been successfully synthesized using the... more High aspect ratio of WO3-loaded TiO2 nanotube arrays have been successfully synthesized using the electrochemical anodization method in an ethylene glycol electrolyte containing 0.5 wt% ammonium fluoride in a range of applied voltage of 10-40 V for 30 min. The novelty of this research works in the one-step formation of WO3-loaded TiO2 nanotube arrays composite film by using tungsten as the cathode material instead of the conventionally used platinum electrode. As compared with platinum, tungsten metal has lower stability, forming dissolved ions (W 6+ ) in the electrolyte. The W 6+ ions then move towards the titanium foil and form a coherent deposit on titanium foil. By controlling the oxidation rate and chemical dissolution rate of TiO2 during the electrochemical anodization, the nanotubular structure of TiO2 film could be achieved. In the present study, nanotube arrays were characterized using FESEM, EDAX, XRD, as well as Raman spectroscopy. Based on the results obtained, nanotube arrays with average pore diameter of up to 74 nm and length of 1.6 µm were produced. EDAX confirmed the presence of tungsten element within the nanotube arrays which varied in content from 1.06 at% to 3.29 at%. The photocatalytic activity of the nanotube arrays was then investigated using methyl orange degradation under TUV 96W UV-B Germicidal light irradiation. The nanotube with the highest aspect ratio, geometric surface area factor and at% of tungsten exhibited the highest photocatalytic activity due to more photo-induced electron-hole pairs generated by the larger surface area and because WO3 improves charge separation, reduces charge carrier OPEN ACCESS Materials 2015, 8 2140 recombination and increases charge carrier lifetime via accumulation of electrons and holes in the two different metal oxide semiconductor components.
In this paper, a facile electrodeposition synthesis was introduced to prepare the nanodisk-dendri... more In this paper, a facile electrodeposition synthesis was introduced to prepare the nanodisk-dendritic ZnO film using a mixture solution of zinc chloride (ZnCl2) with potassium chloride (KCl) acted as a directing agent. This study aims to determine the best photoelectrochemical response for solar-induced water splitting. Based on our results obtained, it was found that an average diagonal of nanodisk was approximately 1.70 µm with the thickness of ≈ 150 nm in thickness was successfully grown on the surface of substrate. The photocatalytic and photoelectrochemical response of the resultant wurtzite type based - nanodisk-dendrite ZnO film as compared to the as-prepared ZnO film were monitored and evaluated. A photocurrent density of 19.87 mA/cm2 under ultraviolet rays and 14.05 mA/cm2 under visible light (500nm) was recorded for the newly developed nanodisk-dendritic ZnO thin film. It was believed that nanodisk-dendritic ZnO film can harvest more incident photons from the illumination to generate more photo-induced charge carriers to trigger the photocatalytic and photoelectrochemical reactions. Moreover, strong light scattering effects and high specific surface area of 2D-nanostructures aid for the incident light absorption from any direction.
High aspect ratio of WO3-loaded TiO2 nanotube arrays have been successfully synthesized using the... more High aspect ratio of WO3-loaded TiO2 nanotube arrays have been successfully synthesized using the electrochemical anodization method in an ethylene glycol electrolyte containing 0.5 wt% ammonium fluoride in a range of applied voltage of 10-40 V for 30 min. The novelty of this research works in the one-step formation of WO3-loaded TiO2 nanotube arrays composite film by using tungsten as the cathode material instead of the conventionally used platinum electrode. As compared with platinum, tungsten metal has lower stability, forming dissolved ions (W 6+ ) in the electrolyte. The W 6+ ions then move towards the titanium foil and form a coherent deposit on titanium foil. By controlling the oxidation rate and chemical dissolution rate of TiO2 during the electrochemical anodization, the nanotubular structure of TiO2 film could be achieved. In the present study, nanotube arrays were characterized using FESEM, EDAX, XRD, as well as Raman spectroscopy. Based on the results obtained, nanotube arrays with average pore diameter of up to 74 nm and length of 1.6 µm were produced. EDAX confirmed the presence of tungsten element within the nanotube arrays which varied in content from 1.06 at% to 3.29 at%. The photocatalytic activity of the nanotube arrays was then investigated using methyl orange degradation under TUV 96W UV-B Germicidal light irradiation. The nanotube with the highest aspect ratio, geometric surface area factor and at% of tungsten exhibited the highest photocatalytic activity due to more photo-induced electron-hole pairs generated by the larger surface area and because WO3 improves charge separation, reduces charge carrier OPEN ACCESS Materials 2015, 8 2140 recombination and increases charge carrier lifetime via accumulation of electrons and holes in the two different metal oxide semiconductor components.