Fariza Mohamad

Electrodeposition of 1.4-eV-Bandgap p-Copper (II) Oxide Film With Excellent Photoactivity

A p-type semiconductor CuO film with a bandgap energy of 1.4 eV has been prepared by anodic electrodeposition in a basic aqueous solution containing copper nitrate hydrate and ammonium nitrate at 297 K, and the structural, optical, and electrical characterizations were carried out. The randomly-oriented CuO film prepared on a transparent conductive glass substrate showed electrical characteristics of a 1.26 x 10 3 Ω cm in resistivity, 2.11 x 10 16 cm -3 in carrier concentration, and 0.234 cm 2 V -1 s -1 in mobility, and a slight photocurrent generation could be observed during light irradiation. The (002)-oriented CuO film could be prepared on the (111)-oriented Au/Si wafer substrate and possessed an excellent photoactivity of a large photocurrent density and quick response compared to those for the randomly oriented CuO film.

Electrodeposited ZnO—Nanowire/Cu2O Photovoltaic Device with Highly Resistive ZnO Intermediate Layer

Cl-doped ZnO-nanowire (Cl:ZnO-nws)/Cu2O photovoltaic devices were prepared by electrodeposition in aqueous solutions, and the effects of the insertion of the highly resistive ZnO (i-ZnO) layer has been demonstrated by an improvement of the photovoltaic performance. The Cl:ZnO-nws and i-ZnO layer were prepared by electrodeposition in a zinc chloride aqueous solution with saturated molecular oxygen and simple zinc nitrate aqueous solution, respectively. The i-ZnO layer was directly deposited on the Cl:ZnO-nws and suppressed the electrodeposition of the Cu2O layer on the Cl:ZnO-nws. The insertion of the i-ZnO layer between the Cl:ZnO-nws and Cu2O layers induced an improvement in the photovoltaic performance from 0.40 to 1.26% with a 0.35 V open circuit voltage, 7.1 mA·cm(-2) short circuit current density, and 0.52 fill factor due to the reduction of the recombination loss.

Cyclic voltammetry measurement for n-type Cu2O thin film using copper sulphate-based solution

Cuprous oxide (Cu2O) is a promising material for solar cell application. Due to its various advantages over silicon material, it has been exploited extensively to be use in photovoltaic cell. Cu2O thin films were electrodeposited in sulfate-based solution. Cyclic voltammorgram (CV) measurement was used to investigate the reduction process under controlled parameters. Deposition potential of-0.1V vs. Ag/AgCl was used for the fabrication of Cu2O thin film based on the CV measurement. CV also revealed that the deposition speed was dependent on the bath pH and the temperature. X-ray diffraction (XRD) measurement, Field Emission Scanning-Electron Microscopy (FE-SEM) and Ultraviolet-visible spectroscopy (UV-Vis) were performed to characterize the deposited thin films. The n-Cu2O was successfully fabricated on FTO glass substrate with (111)-prefered orientation. Surface morphology of the thin films were observed to be in flower-like shape combination with pyramidal and triangular shape.

Growth Mechanism of Copper Oxide Fabricaticated by Potentiostatic Electrodeposition Method

This experiment is about fabrication of n-type Cu2O thin film on fluorine doped thin oxide (FTO) glass by using copper acetate based solution through potentiostaticelectrodeposition. A range of deposition time was carried out from 20 to 40 minutes and the results were obtained. The other parameters such as potential deposition, bath temperature and pH value of solution were kept constant for-0.125Vvs Ag/AgCl, 60 °C and pH 6.3, respectively. It was found that the optimum deposition time for growth mechanism of n-type Cu2O thin film was 30 minutes. Structural, morphologicaland optical properties were characterized by using X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), and Ultraviolet and visible Absorption Spectroscopy (UV-Vis), respectively. The successfully fabrication of n-Cu2O was confirmed using PEC measurement result.

Carbon Sequestration and Carbon Capture and Storage (CCS) in Southeast Asia

Southeast Asia is a standout amongst the most presented districts to unnatural weather change dangers even they are not principle worldwide carbon dioxide (CO2) maker, its discharge will get to be significant if there is no move made. CO2 wellsprings of Southeast Asia are mainly by fossil fuel through era of power and warmth generation, and also transportation part. The endeavors taken by these nations can be ordered into administrative and local level. This paper review the potential for carbon catch and capacity (CCS) as a part of the environmental change moderation system for the Malaysian power area utilizing an innovation appraisal structure. The countrys recorded pattern of high dependence on fossil fuel for its power segment makes it a prime possibility for CCS reception. This issue leads to gradual increment of CO2 emission. It is evident from this evaluation that CCS can possibly assume a vital part in Malaysias environmental change moderation methodology gave that key criteria are fulfilled. With the reason to pick up considerations from all gatherings into the earnestness of an Earth-wide temperature boost issue in Southeast Asia, assume that more efficient measures can be taken to effectively accomplish CO2 diminishment target.

Feasibility Study of Waste Motor Recycling through Manual Dismantling and Hydrometallurgical Process

Huge amount of waste electrical and electronic equipments (WEEE) or electronic waste (E-waste) has been produced every year in the world. It consists of valuable and hazardous metals that can be reused or extracted to minimize the environmental impact. This study is focusing on the investigation of recycling potential of e-waste through manual dismantling process and leaching test. The leaching test was conducted by changing the initial pH with constant stirring speed, constant water-sample ratio and in open air. The morphological structures of the solid samples were observed by SEM and the liquid residue was analyzed by Atomic Absorption Spectroscopy (AAS). It was found that total time required to dismantle all parts in the waste motor is about 10 minutes and the part that required longest dismantling time was armature windings. The metal elements that were observed are Fe, Mg, Pb and Cr. It was found that the pH of the solution increased with the increasing leaching time. The dissolution of Fe and Pb was high in the early stage of leaching but gradually decreased afterward. The dissolution for Mg and Cr was low throughout the leaching process. It was revealed that the metal elements in e-waste can be dissolved using this method and further investigation to increase the dissolution rate is required to ensure that the method proposed is applicable in industry. However, dissolved concentration of Pb must be controlled to ensure that it follows the permissible amount set under environmental standard.

Effect of Pressure on the CO2 Absorption into Ladle Furnace Slag

Carbon dioxide (CO2) is one of the greenhouse gases (GHG) and the concentration is much more higher than other GHG gases. Based on the prediction, about 285.73 million tonnes will be emitted in year 2020 with the main contributors are from power generation, manufacturing industries, transportation and residential sector [1]. This research focused to study the effect of pressure on the CO2 absorption with Malaysia steel slag using mechanical stirrer. The steel slag is collected from one of steel industry located in Pasir Gudang Johor Malaysia and characterized to investigated the chemical composition. The reaction between CO2 absorption and the slag was investigated by using different speed and weight. The initial pressure was set at 101.3 kPa which equivalent with 1 atmospheric pressure. The behavior of the reaction between CO2, and ground sample was investigated by measuring the change in the CO2 pressure inside the mechanical stirrer. It was found that the CO2 pressure decreased as soon as the stirrer started and continuously decreased till bout 270 t/min stirring time.

Cyclic Voltammetry Measurement for Cu2O Based Homostructure Thin Film

This experiment is about fabrication of homojunction Copper Oxide (Cu2O) thin film by using electrodeposition method. The p-n homojunction Cu2O was successfully prepared by consecutively depositing p-type Cu2O layer on n-type Cu2O layer by using copper acetate based solution through potentiostatic electrodeposition. At first, the n-type Cu2O was fabricated at pH 6.2 and 6.5 with fixed potential of -0.125V vs Ag/AgCl and time deposition at 30 minutes. Cyclic voltammetry (CV) measurement was carried out on this sample to determine the ideal potential range for fabrication of p-type Cu2O on n-type Cu2O/FTO substrate. From the result, deposition potential of -0.35V and -0.4V vs Ag/AgCl were appropriated for p-type Cu2O thin film fabrication. These potential values were variable with the selected pH values of 12.0 and 12.5 to fabricate the p-type Cu2O thin film. The other parameters such as deposition time fixed at 2 hours bath temperature was set up at 60°C. It was found that the optimum potential deposition was -0.4V vs Ag/AgCl and pH value appropriate for homostructure Cu2O thin film was pH 12.5. Morphological, structural, optical and conductivity characterization of p-n homojunction Cu2O thin film was characterized using Field Emission Scanning Electron Microscopy, X-Ray Diffractometer, Ultraviolet-Visible Spectroscopy and Photoelectrochemical (PEC) cells, respectively.

Hydrophobic rutile phase TiO2 nanostructure and its properties for self-cleaning application

The nanostructured hydrophobic rutile phase titanium dioxide TiO2 and its properties for self-cleaning application were directly synthesized from titanium butoxide (TBOT) precursor deposited on the fluorine doped tin oxide (FTO) substrate through the hydrothermal treatment with different volume of TBOT and adding of Cetyl Trimethylammonium Bromide (CTAB). The samples were characterized respectively by way of field-emission scanning electron microscopy (FE-SEM), water contact angle measurement and Raman spectroscopy for surface analysis system. The FE-SEM results revealed a layer of nanoparticles were growth on the FTO substrate. The surface properties of the samples were studied with a water contact angle measurement. The water contact angle measurement results revealed the hydrophobic of samples as the angle of water droplet on the sample increased. The rutile phase and surface of TiO2 were confirmed using a Raman spectroscopy.The nanostructured hydrophobic rutile phase titanium dioxide TiO2 and its properties for self-cleaning application were directly synthesized from titanium butoxide (TBOT) precursor deposited on the fluorine doped tin oxide (FTO) substrate through the hydrothermal treatment with different volume of TBOT and adding of Cetyl Trimethylammonium Bromide (CTAB). The samples were characterized respectively by way of field-emission scanning electron microscopy (FE-SEM), water contact angle measurement and Raman spectroscopy for surface analysis system. The FE-SEM results revealed a layer of nanoparticles were growth on the FTO substrate. The surface properties of the samples were studied with a water contact angle measurement. The water contact angle measurement results revealed the hydrophobic of samples as the angle of water droplet on the sample increased. The rutile phase and surface of TiO2 were confirmed using a Raman spectroscopy.

Fabrication of TiO2 nanostructures on porous silicon for thermoelectric application

Nowadays, technology is moving by leaps and bounds over the last several decades. This has created new opportunities and challenge in the research fields. In this study, the experiment is about to investigate the potential of Titanium Dioxide (TiO2) nanostructures that have been growth onto a layer of porous silicon (pSi) for their thermoelectric application. Basically, it is divided into two parts, which is the preparation of the porous silicon (pSi) substrate by electrochemical-etching process and the growth of the Titanium Dioxide (TiO2) nanostructures by hydrothermal method. This sample have been characterize by Field Emission Scanning Electron Microscopy (FESEM) to visualize the morphology of the TiO2 nanostructures area that formed onto the porous silicon (pSi) substrate. Besides, the sample is also used to visualize their cross-section images under the FESEM microscopy. Next, the sample is characterized by the X-Ray Diffraction (XRD) machine. The XRD machine is used to get the information about the...