Fabrication and characterization of crystalline cupric oxide (CUO) films by simple immersion technique

Cupric oxide (CuO) is one of the most promising p-type semiconducting materials used in p-n junction solar cells. Most of the researchers use electrochemical deposition (ECD) to deposit CuO film. However, it always requires a conductive substrate and the resulting film is porous. In this work, we demonstrated a simple method using an immersion technique to deposit nanostructured CuO for p-n solar cell application. Compared to ECD which end up with only pyramid-like structure, an immersion technique offers flexibility on the CuO nanostructures such as spheres, particles, diamond etc. This technique also offers higher deposition rate which allow deposition at thicker thickness. The adherence to the substrate can be manipulated depending on the pH of the solution. The resuling film was tested into a p-n solar cell using configuration of Au/ZnO/Cuo/ITO/glass. Although there is no efficiency obtained under the solar radiation, it shows a solar cell characteristic with open circuit voltage (Voc) of 1.5

Structural and Electrical Properties of TiO2 Thin Film Derived from Sol-gel Method using Titanium (IV) Butoxide

Fabrication of titanium dioxide (TiO2) thin film on microscope glass using sol-gel method has been studied intensively. The starting materials were titanium (IV) butoxide, ethanol, acetic acid, triton x-100, hydrochloric acid and deionized water. The materials were mixed together to form the sols. Then, the heat and ageing treatment was applied to form stable sols. The sols were then spin coated on the glass substrate to form the homogenous and transparent TiO2 thin film. The TiO2 thin film was coated at several layers using specific conditions. To evaluate the performance of thin film, the crystallinity of the thin film was determined by using the x-ray diffractometer  (XRD). The change on the surface morphology was observed using atomic force microscope (AFM). The electrical property of the thin film was determined by doing the current-voltage (I-V) analysis on the thin film. It has been successfully shown that the anatase crystalline phase was observed when the TiO2 thin film was heated at 500°C. The roughness and the crystalline phase of TiO2 thin film changed drastically with the growth conditions. Finally, the effect of film preparation to the film resistivity also showed a critical aspect where we should take into account during the preparation of TiO2 thin film

Manufacturing and Morphological Analysis of Composite Material of Polystyrene Nanospheres/Cadmium Metal Nanoparticles

A very simple nanocomposite material has been in-situ manufactured from an aqueous polystyrene nanospheres dispersion and cadmium (Cd) metal nanoparticles. The manufacturing was performed by using a high frequency of 40 kHz ultrasonic (US) agitation for 45 minute at atmospheric pressure and at room temperature 20 oC. No chemical reducing agent and surfactant added in this manufacturing technique due to the US could reduce Cd2+ ions of cadmium nitrate tetrahydrate to Cd atomic metals nanoparticles whereas water molecules could act as a pseudo stabilizer for the manufactured material. A thin film was manufactured from aqueous colloidal nanocomposite material of Polystyrene nanospheres/Cd metal nanoparticles (PSNs/CdMNp) fabricated on a hydrophilic silicon wafer. The thin film was then characterized by a JEOL-FESEM for its surface morphology characteristic and by ATR-FTIR spectrometry for its molecular change investigation. It could be clearly observed that surface morphology of the thin film material was not significantly changed under 633 nm wavelength continuous laser radiation exposure for 20 minute. In addition, its ATR-FTIR spectra of wave number peaks around 3400 cm-1 have been totally disappeared under the laser exposure whereas that at around 699 cm-1 and 668 cm-1 have not been significantly changed. The first phenomenon indicated that the hydrogen bond existed in PSNs/CdMNp material was collapsed by the laser exposure. The second phenomena indicated that the PSNs phenyl ring moiety was not totally destroyed under the laser exposure. It was suspected due to the existence of Cd nanoparticles covered throughout the spherical surface of PSNs/CdMNp material particles. Therefore a nice model of material structure of the mentioned PSNs/CdMNp nanocomposite material could be suggested in this research. It could be concluded that this research have been performed since the material structure model of the manufactured PSNs/CdMNp nanocomposite could be drawn and proposed © 2013 BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME) 2012)Received: 26th September 2012; Revised: 17th December 2012; Accepted: 18th December 2012[How to Cite: P. J. Wibawa, H. Saim, M. A. Agam, H. Nur, (2013). Manufacturing and Morphological Analysis of Composite Material of Polystyrene Nanospheres/ Cadmium metal nanoparticles. Bulletin of Chemical Reaction Engineering &amp; Catalysis, 7 (3): 224-232. (doi:10.9767/bcrec.7.3.4043.224-232)][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.7.3.4043.224-232 ] View in  | </p

Defective TiO2 with intrinsic point defects for photocatalytic hydrogen production: A review

Link to publisher's homepage at http://ijneam.unimap.edu.myTitanium dioxide (TiO2) has been intensively investigated for solar hydrogen conversion via photocatalytic and photoelectrochemical water splitting. However, the performance of TiO2 photocatalyst for hydrogen generation is low due to the rapid electron-hole recombination and its wide band gap (3.0-3.2 eV) which is only feasible for UV light absorption of solar spectrum. There are various strategies have been used for TiO2 modification to harvest the sunlight and improve the surface chemical reaction between TiO2 and H2O for water splitting. Among the TiO2 modification strategies, intrinsic point defects such as vacancies and interstitials in TiO2 have been proven to improve the TiO2 properties for photo-catalytic activity. In this article, the recent progress achieved in defective TiO2 with intrinsic point defects for photocatalytic hydrogen evolution and photoelectrochemical water splitting has been reviewed. The fabrication methods of defective TiO2 along with their structural, optical, and charge carrier properties have been introduced. It has appeared that the intrinsic point defects are a promising strategy to improve the performance of TiO2 for photocatalytic hydrogen production, and more efforts are still needed to improve the TiO2 performance for photocatalytic hydrogen production in this area of research

Tensile properties of 3D-printed PLA prismatic cellular structures: an experimental investigation

Advancements in additive manufacturing have significantly increased the use of cellular structures in product development, especially in the automotive, aerospace, and biomedical industries, due to their enhanced strength-to-weight ratio and energy-absorbing capabilities. This study investigates the tensile properties of 3D-printed PLA prismatic cellular structures, focusing on the effects of fillet radius, wall thickness, and cell size on tensile strength, Young’s modulus, and strength-to-weight ratio. Using a full factorial design and ANOVA, we examined the impact and interaction of each geometrical parameter. Our findings show that triangular cellular structures exhibit a higher stiffness of 1.36 GPa and tensile strength of 24.28 MPa, resulting in a notable 5.78 MPa/gram strength-to-weight ratio. Increasing cell count and wall thickness enhances both tensile strength and Young’s modulus, whereas adding fillet radii at corners reduces these properties. Fracture behaviors are influenced by geometrical design: shorter, thicker walls lead to progressive crack propagation, while longer, thinner walls tend to fail catastrophically. Fillet radius introduction shifts the fracture initiation point from the nodes. ANOVA results indicate that wall thickness and cell size significantly affect tensile strength and Young’s modulus, contributing 36.53% and 53.54%, respectively

Development of a Wireless and Ambulatory Posture Monitoring System

The wireless and ambulatory posture monitoring system monitors the movement and posture change of the human body with respect to the g-line. It is crucial to monitor the posture health of the ophthalmologist who spends a prolonged period on the static sitting posture while operating on the slit lamp which leads to any painful experience. The motivation of the proposed system is to improve the ergonomics of the ophthalmologist on their working environment and reduce any occupational potential hazard which may prompt Work-Related Musculoskeletal Disorders (WMSDs). The proposed system also induced a wireless system by using XBee wireless units to reduce the use of the wire that may tangle on the study subject which causes any uncomfortable experience to the study subject during the human trial. Inertial Measurement Unit (IMU) sensor which consists of an Accelerometer, a Gyroscope and a Magnetometer is used to measure the angle of deviation of the body segment with respect to the g-line. The data is tabulated and presented into the graphical method to identify and extract the properties of the graph on each different static sitting posture which later are used for posture recognition

Rapid response room temperature oxygen sensor based on Trivalent-Elements doped TiO2 thin film

Link to publisher's homepage at http://ijneam.unimap.edu.myTrivalent metal-doped TiO2 thin films have been extensively investigated in gas sensor applications. The trivalent metal dopants are Al, Y and Gd. The trilayer fabrication of a gas sensor consists of a thin film, sputtered TiO2 and Au nanoparticles. The characteristics of the gas sensing properties are strongly correlated with the annealing temperature, film thickness, type of doping and deposition method. The subsequent properties are presented – the crystalline structure, grain size, roughness, strain, stress and defects. Thin films have been developed with concentrations of O2 gas up to 10 sccm. A response time for O2 gas in milliseconds was obtained at room temperature. Al doped TiO2 thin film have a faster response time operating at room temperature compared with other thin films. Oxygen vacancy defects also contribute to the speed of the response time for a gas sensor

Preparation of pervaporation membrane using a-type zeolite filled chitosan membrane for the separation of isopropanol/water mixtures

The novel polymeric membranes were prepared by incorporating the NaA zeolite into chitosan and were subjected for the pervaporation separation of water-isopropanol mixtures. The resulting membranes were characterized by Fourier transform infrared spectroscopy (FTIR). The effects of zeolite loading and feed composition on the pervaporation performance of the membranes were analyzed. The membranes were tested for its mechanical properties in terms of tensile strength, elongation and Young’s Modulus. The incorporated membrane showed an increase in strength and elongation until it reached its optimum value of 0.3 weight % of zeolite loading in the membrane. The experimental results showed that both flux and selectivity increased with the addition of zeolite content in the membrane. This was explained on the basis of enhancement of hydrophilicity, selective adsorption and molecular sieving action by creation of pores in the membrane matrix

Cadmium Metals Particles-Covered Polystyrene Nanospheres Thin Film Material:Fabrication, Analysis and Model

It was well known that cadmium metals particles-covered 200 nm Polystyrene Nanospheres (PSNs) thin film material could be prepared from its according colloidal metals precursor of cadmium nitrate tetrahydrate, Cd(NO3)2.4H2O in water-polyvinil pyrrolidone (PVP) homogeneous mixture. After reducing it with sodium borohidride, NaBH4 then thin films of the colloidal were fabricated on a hydrophilic silicon wafer through gently dropping method and subsequently it was analyzed by both analytical isntruments of ATR-FTIR spectrometry and FESEM. It was clearly observed that wave number ranges of 1700-1600 cm-1 and 1500-1200 cm-1 generated signficant different ATR-FTIR spectra between pristine PSNs and cadmium-covered PSNs. In addition, surface morphology of pristine PSNs thin film explored with FESEM revealed sharply different from that of cadmium-covered PSNs one. It indicated that PSNs particles surface have succesfully been fully covered by cadmium metals particles. Therefore it could be concluded that cadmium metals particles-covered PSNs thin film could be fabricated from its according colloidal precursor and the model might be ilustrated as the following Fig. 2