Muhd Zu Azhan Yahya

Muhd Zu Azhan Yahya
National Defence University of Malaysia | UPNM · Department of Defense Science

About

211
Publications
56,219
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2,376
Citations
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March 2012 - June 2016
National Defence University of Malaysia
Position
  • Professor (Full)

Publications

Publications (211)
Article
Full-text available
First-principles calculations with density functional theory (DFT) were carried out to explore the effects of Hubbard on-site Coulombic correction on the structural and electronic properties of wurtzite zinc oxide (ZnO). For an accurate prediction of ZnO properties, adequate Hubbard terms must be established due to changes in structural parameters...
Article
In this work, the first-principles calculations using density functional theory (DFT) was applied to calculate the structural and electronic properties of anatase, rutile and brookite TiO2 phases. The effects of Hubbard U correction on the structural and electronic properties of rutile, anatase TiO2 were explored using the local density approximati...
Article
Titanium dioxide (TiO2) and TiO2 doped with impurities offer good potential for many applications such as photoanode in dye-sensitized solar cells (DSSCs) and photocatalysts used in hydrogen production and degradation of organic pollutants. First-principles calculations on the structural, electronic and optical properties of pure anatase TiO2 with...
Article
Variation of surface chemical energy and its effects on adhesion strength and corrosion protection properties of epoxy coatings of mild steel substrates were studied. Results indicated that pre-treatment with a mixture of 3-glycidoxypropyltrimethoxysilane, sodium dodecylbenzene sulphonates and zinc sulphate inhibitors enhanced the corrosion protect...
Article
This study explored the electronic and optical properties of nano-thin film orthorhombic bismuth selenide (Bi2Se3) using first-principles approach. The thin films were modelled in the [001] direction using slab geometry supercell with vacuum along z-direction so that periodic images and slab can be managed independently. We obtained band gap of 0.7...
Article
PbTiO3 has emerged as a promising material for the thermoelectric application. In this study, we proposed to use density functional theory to investigate the underlying mechanism for improving the thermoelectric efficiency of ATiO3. The thermoelectric parameters of the designed surface structures have been obtained by using the Boltzmann transport...
Article
Full-text available
On the basis of ab initio calculation, we reported the structural and electronic properties of the nickel (Ni) substitution on the cobalt oxide (Co 3 O 4 ) to produce nickel cobaltite (NiCo 2 O 4 ) using generalized gradient approximation + U parameter (GGA + U) calculation method. The spinel NiCo 2 O 4 with half-metallic behaviour has a relatively...
Article
Full-text available
Direct conversion of waste heat to electrical energy could address present energy challenges. Bi2Se 3 is one of few thermoelectric materials known to operate at room temperature. Comprehensive analysis using density functional theory was conducted to explore the effect of nickel doping on structural, electronic, and thermoelectric properties of Bi2...
Article
Structural, electronic and optical properties of nickel (Ni) doped bismuth selenide (Bi2Se3) in orthorhombic phase was studied via first principles approach using density functional theory (DFT). A generalized gradient approximation (GGA) for Perdew-Burke-Ernzerhof for solids (GGA-PBEsol) was employed as functional of exchange-correlation. The stru...
Article
Graphene-Zinc Oxide (Gr-ZnO) nanocomposites films were successfully synthesized via facile electrodeposition method in an aqueous solution under Gr concentration conditions. Gr, as a highly conductive carbon, acts as an anchor for ZnO nanosheets and plays a substantial role in controlling the degree of dispersion of ZnO nanosheets onto indium-doped...
Article
Full-text available
The morphology and electrochemical properties of electrodes made from graphene (Gr)-activated carbon (AC) composite (GrAC) doped with iron(III) tetramethoxyphenylporphyrin chloride (FeTMPP-Cl), hereafter referred to as GrAC-FeTMPP-Cl, are investigated in this study. The properties of the modified electrodes are considerably improved by modifying ca...
Article
Thermoelectric materials regain attention due to its capability as a solution of the environmental crisis. Bi2Te3 is one of the most efficient thermoelectric materials known that capable to operate at room temperature. A comprehensive analysis was conducted using density functional theory (DFT) that implemented in CASTEP to perform structural optim...
Article
Full-text available
Prussian blue, Fe[Fe(CN)6] currently attracts a huge attention as a promising material in the application of large-scale energy storage because of its cost-effective and environmental friendly material. Besides, open framework structure and stability are the main causes for PB performance. In this study, effects of sodium cation insertion/deinserti...
Article
Full-text available
BiFeO3 is the only multiferroic materials that present both spontaneous magnetic and electric polarizations at room temperature. However, the weak magnetization (almost zero) have been measured in bulk BiFeO3 materials which prevent it to be applied in multiferroic based devices. Therefore, the modification on the crystal structure of BiFeO3 materi...
Article
The effect of CO and NO adsorption on graphene (pristine, vacancy and doped) were investigated for structural and electronic properties. The sensitivity of palladium (Pd) doped graphene toward small gas molecules CO and NO have been investigated by using DFT calculation within Generalized Gradient Approximation (GGA) as implemented in DMol³ and CAS...
Article
First principles calculations within framework of the density functional theory (DFT) have been carried out to investigate structural, electronic and optical properties of zinc doped magnesium oxide (ZnxMg1−xO) with different zinc concentration (x = 0, 0.125 and 0.25). The crystal structure used in this calculation was cubic MgO with space group of...
Article
This study investigates the effect of oxalic acid at different concentrations as doping agent on the electrical properties of polyaniline (PANI). The polymerization of aniline to produce PANI was carried out in media containing oxalic acid at 0.08 M, 0.09 M, 0.1 M, 0.2 M and 0.3 M in the presence of ammonium persulphate as oxidizing agent. The succ...
Conference Paper
Full-text available
Port Klang is one of the busiest ports in the worlds and have played an important role to ensure the import and export activities towards Malaysian economy sector. Port Klang located in a busy marine sea route of Strait of Malacca received a great amount of vessels making it a high density port and more likely exposed to the collision risk. From th...
Article
Ground state, structural, and magnetic phase transitions of strained BiVO3 were investigated using the first-principles calculation based on the self-interaction corrected local density approximation + U functional. The calculated total energy indicated that the ground state structure for BiVO3 was a monoclinic P21/a phase and ferromagnetic orderin...
Conference Paper
Thiazole-4-carboxamide (Th) has been prepared as ionophore in an electrochemical setup of a cadmium ion selective electrode (ISE). There are four components in liquid polymeric membrane consist of thiazole-4-carboxamide (Th) as an ionophore, polyvinyl chloride (PVC) as a polymeric matrix, sodium tetra phenyl borate (NaTPB) as an ionic additive and...
Article
Full-text available
The increasing energy demand on available global lithium resources has created concerns on development of new and advanced sustainable energy sources. Sodium-based batteries have emerged as promising substitutions to Li-based batteries. We describe here sodium trifluoromethanesulfonate (NaCF3SO3) electrolyte system based on tetraethylene glycol dim...
Article
This paper reports the fabrication of a lithium ion supercapacitor from vertically-aligned carbon nanotubes (VACNTs) directly grown on a conductive substrate (SUS 310S alloy), using alcohol catalytic chemical vapour deposition technique. CNTs direct growth technique on an electrically conducting foil simplifies the electrode assembly, thus reducing...
Article
A comparative study of structural, electronic and magnetic Ca²⁺, Sr²⁺ and Ba²⁺ A-site ion substitution of BiFeO3 with different Fe oxidation states was carried out. Calculation shows doped compounds favours energy stability in Fe oxidation states of 2+ and 4+ compared to 3+ charge. Electronic band gap makes significant changes with value of 1.32 eV...
Article
First-principles calculations using density functional theory (DFT) have been performed to investigate the structural and electronic properties of TiO2 polymorphs in rutile, anatase and brookite phases. The calculations based on local density approximation (LDA) and generalized gradient approximation (GGA) for Perdew-Burke-Ernzerhof (PBE) and Perde...
Conference Paper
Structural and electronic properties of tetragonal (space group P4mm) of PbLaTiO3 and PLaZT are investigated using pseudopotential plane wave method within the local density approximation (LDA) and generalized gradient approximation (GGA) with virtual crystal approximation (VCA) calculation. The calculated structural parameters for PbLaTiO3 and PLZ...
Conference Paper
Composite grafted polymer electrolyte based on chitosan grafted poly(methyl methacrylate) (Ch-g-PMMA) have been prepared and investigated. The lithium triflouromethanesulfate salt (LiCF3SO3 or LiTf), ethylene carbonate (EC) and SiO2 and are applied as a salt, plasticizer and ceramic filler, to the polymer host systems. Impedance spectroscopy was pe...
Conference Paper
Polymer gel electrolytes based on potato starch as biopolymer and potassium hydroxide salt are prepared. The ionic conductivity and dielectric constant of the polymer gel electrolyte samples are investigated using electrochemical impedance spectroscopy over a frequency range from 50 Hz to 1 MHz. The optimum room temperature conductivity attained fo...
Conference Paper
Acrylates such as poly (methyl methacrylate) (PMMA) has been widely studied as a polymer electrolyte film due to its good mechanical stability towards lithium electrode. However, commercial PMMAs even at high molecular weight were not able to produce a flexible film due to its polar nature that is prone to form interchain crosslinking via hydrogen...
Conference Paper
First-principles calculations on phase stability of three polymorphs of titanium dioxide (TiO2) in rutile, anatase and brookite phases are performed using density functional theory (DFT) and density functional theory plus Hubbard U (DFT+U) methods within generalized gradient approximation (GGA) for Perdew-Burke-Ernzerhof for solids (GGA-PBEsol) fun...
Article
Full-text available
Gun powder is predicted to be more expensive in relation to the world oil shortage crisis in the future. However, cellulose (generic chemical formula (C6H10O5) is the carbohydrate that makes up the main structure of plants. It is more economical especially for countries with a lot of natural resources and rain forests like Malaysia. The finding of...
Article
Full-text available
Natural pigments such as anthocyanin, carotenoid, flavonoids, and chlorophyll can be considered as promising alternative sensitizer dyes for DSSC to replace synthetic dye such as N719 because of their simple preparation technique, low cost, complete biodegradation, availability, purity grade, environmental friendliness and most importantly ability...
Article
Full-text available
The normal spinel cobalt oxide Co3O4 is considered as a magnetic semiconducting material comprising of cobalt ions with two oxidation states of Co2+ and Co3+. Density Functional Theory (DFT) calculation are employed to generate the structural, electronic and optical properties using Generalized Gradient Approximation (GGA) function. The Perdew-Burk...
Article
30% poly(methyl methacrylate) grafted natural rubber was treated with N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) additive (TMG30) to retard its degradation before further used as electrolytes. The polymer electrolytes containing MG30-6PPD-LiTF were prepared by solution cast technique. X-ray diffraction studies show the electrolytes w...
Article
Microbial Fuel Cell (MFC) is an alternative method of renewable energy which have gained considerable attention due to its capability to generate electricity and treat wastewater such as palm oil mill effluent (POME). MFC’s mechanism on its electrochemical process is still lacking and further studies is needed. The objectives of this study are (1)...
Article
Full-text available
Electrical dielectric spectra and alternating current (ac) conductivity of blended poly (N-vinlycarbazole) (PVK) with polyvinylpyrrolidone (PVP) at different temperature are investigated. The polymer blends were prepared by dissolving in dimethylformamide (DMF) using drop casting method and further dried in vacuum oven. The dielectric and ac conduc...
Article
Full-text available
The mixture between the difference semiconductor quantum dot sensitizer which is cadmium selenide(CdSe) and zinc sulfide (ZnS) into the Dye-synthesis solar cell (DSSCs) can affect the value of resistance and capacity photoanode in the system.In this experiment, each sample consists difference weight percent of Zinc sulfide and the constant weight p...
Article
Full-text available
The absorption rate of the photoanode can be influenced by the combination between the difference semiconductor quantum dot sensitizer. Six samples were prepared with difference weight percent (wt%) of ZnS from 0% to 50% and constant wt% of CdSe which then will be called as semiconductor QDs were immersed in 0.5mM of N719 dye. The purity of ZnS pow...
Article
This work aims to investigate effects of vanadium substitution on structural and electronic properties of the pristine LiFeSO4OH compound using GGA, GGA+U and GGA + van der Waals (vDW) dispersion corrections. Upon vanadium substitution, the band gap of substituted vanadium on LiFeSO4OH decreased implying the increase in electronic conductivity, thu...
Article
First principles calculations on structural, electronic and optical properties of the orthorhombic phase (No. 62: Pnma space group) lead-free Sn(II) hybrid halide perovskite CH3NH3SnI3 were systematically carried out. Work on Pb(II)-based CH3NH3PbI3 hybrid halide perovskite of the same space group is also included for comparative purposes. All calc...
Conference Paper
Full-text available
A series of mesoporous carbon sample was synthesized using silica template, SBA-15 with two different pore sizes. Impregnation method was applied using glucose as a precursor for converting it into carbon. An appropriate carbonization and silica removal process were carried out to produce a series of mesoporous carbon with different pore sizes and...
Conference Paper
Polymer gel electrolytes based on cellulose acetate with lithium bis(oxalato)borate salt were prepared by dissolving in γ-butyrolactone solvent. The ionic conductivity and dielectric constant of the polymer gel electrolyte samples are investigated using electrochemical impedance spectroscopy over a frequency range from 100 Hz to 1 MHz. The ionic co...
Conference Paper
The epoxidized 30% PMMA grafted natural rubber (EMG30) was prepared using performic epoxidation method. 1HNMR studies confirm the appearance of epoxy group at 2.71 ppm in MG30 structure. The highest epoxidation content in EMG30 was used as a polymer host in gel polymer electrolyte (GPE) system. GPE film was prepared using 62.3 mol % EMG30, lithium...
Conference Paper
Full-text available
Organic thin film system consisting of Silicone-dammar (SD) polymer resin was prepared and studied with respect to their electrochemical properties. Dammar which is a local plant resin (Dipterocaupacea sp) was mixed with silicone in various compositions and the two components were modified by using a solvent. A thin film layered on glass slaid was...
Conference Paper
Full-text available
A dye-sensitized solar cells (DSSCs) using a nanocomposite (NC) semiconductor film, consisting of graphene layer and ZnO nanosheets (Gr-ZnO) is fabricated by electrodeposition process. The DSSCs based on Gr-ZnO NC were determined via electrochemical impedance spectra (EIS), UV–Visible diffused reflectance spectroscopy (UV-Vis), and photovoltaic per...
Article
In this paper, the efficiency of Iron-Hexacyanoferrate (FeHCF) and Copper-Hexacyanoferrate (CuHCF) as the cathode materials for using in the energy storage application have been investigated using Density Functional Theory. The changes of their lattice parameters due to the insertion of K⁺ cation were explored. It was found that these changes for C...
Conference Paper
Full-text available
This article focuses on polymer-based gel electrolytes because basic features good self-standing characteristics, conductivity, and excellent window stability for supercapacitor devices when compared to aqueous electrolytes. Gel polymer electrolytes (GPEs) based on 30% poly (methyl methacrylate) grafted natural rubber (MG30) doped with ammonium tri...
Article
The structural, electronic and optical properties of PbZrTiO3 (PZT) and PbSnZrTiO3 (PSnZT) have been studied by a quantum-mechanical calculation using a total-energy pseudopotential code. This compound has a tetragonal crystal structure with space group P4mm of a ferroelectric phase. Different compositions of titanium (Ti) and zirconium (Zr) in PZT...
Article
Extensive research of a new multiferroic material has been conducted due to its possibility of existing in more than one ferroic order - for example ferroelectricity, (anti-)ferromagnetism and ferroelasticity - which gives additional functionalities to a material. In this work, the structural, electronic and optical properties of LuFeO3 in the anti...
Article
Ferroelectric materials of lanthanum (La) doped PbZrTiO3 (PLZT) were investigated via first principles study. The structural, electronic and optical properties of PLZT in tetragonal structure (P4mm space group) were performed in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) and local density approxim...
Article
Graphene is a material that has been heavily investigated in many researches due to its beneficial characteristics such as large surface area, low manufacturing cost, high electro conductivity and incredible mechanical strength. Applying the graphene in water-based solvents however can cause agglomeration due to its hydrophobic properties. Research...
Article
0.5 wt.% of N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine (6PPD) was introduced into polymer electrolytes based on 30% poly(methyl-methacrylate) grafted natural rubber (MG30) in order to reduce the aging factor of MG30. The polymer electrolyte without 6PPD was used as control. All samples were prepared by using solution cast techniques. The ef...
Article
Structural, electronic and optical properties of titanium dioxide (TiO2) in brookite phase were studied via first-principles calculations in the framework of density functional theory (DFT). The exchange-correlation functional from local density approximation (LDA) and generalized gradient approximation (GGA) were used to calculate the properties o...
Article
Crystal structures of Bi2O3 and Bi2O3 were calculated using Cambridge serial total energy package (CASTEP) based on the first-principles plane-wave ultrasoft pseudopotential method within local density approximation (LDA) and generalized gradient approximation (GGA) together with Perdew-Burke-Ernzerhof (GGA-PBE) and Perdew-Burke-Ernzerhof revised f...
Article
Full-text available
The thin film of poly(methyl methacrylate) (PMMA) has been widely studied as host in a polymer electrolyte system due to its good mechanical stability towards lithium electrode. However, the brittle property of this film creates additional resistance for the ionic conduction. The addition of ionic liquid (IL) has been noticed to improve the brittle...
Chapter
Full-text available
Polyvinylpyrrolidone (PVP) has widely been used in polymer-based solid state devices due to its unique characteristic in electronic properties. In this chapter, the electronic properties of PVP and its monomer were examined using Semi-Empirical Zerner Modified Intermediate Neglect of Differential Overlap (ZINDO) method of INDO/1 as a parameterizati...
Conference Paper
To understand the electron doping effect into the parent compound BaFe2As2, we have theoretically evaluated phase stability and electronic structure of low temperature nickel (Ni) doped Ba(Fe1-x Ni x)2As2 superconductor. The optimized Fmmm phase are calculated by first principles pseudopotential and plane wave calculations within generalized-gradie...
Article
Full-text available
The optical properties of titanium dioxide (TiO2) in rutile, anatase and brookite phases were investigated via density functional theory (DFT) framework. The Hubbard U term in Ti 3d electrons of the TiO2 phases was introduced to observe the optical behavior with the effect of U parameter. The calculated structural parameters from the optimized TiO2...
Article
High purity BiFeO3 nanoparticles were successfully prepared by employing green and facile biotemplated method which utilised polysaccharides of κ-carrageenan. The particles’ size of BiFeO3 nanoparticles exhibited significant correlations between structural, electronic and optical properties that have been investigated by both experimental and first...
Article
In this study, first principles calculations based on density functional theory were used to evaluate optimized sructures and the total energy of the La doped PbTiO3 tetragonal (P4mm phase group). The calculations were conducted using local density approximation (LDA) functional as implemented in Cambridge Serial Total Energy Package (CASTEP) compu...
Article
In this paper, the effect of substitution of Co by d-valent elements such as Ag and Pt on electronic structure and magnetic properties of full Heusler type Co2FeSi alloys was investigated. Structural study reveals the presence of a small gap in the minority band structure around the vicinity of the Fermi level on Co2FeSi resulting to half-metallic...
Article
A new carbon material viz. graphene has been attracted an increasing research interest owing to its unique electrical and mechanical properties that is useful for the various device applications. The synthesis of graphene from graphene oxide usually involves harmful chemical reducing agents that are toxic and undesirable to human and the environmen...
Article
Proton exchange membrane materials based on sulfonated poly ether ether ketone (SPEEK) with Methyl Cellulose (MC) are developed by solution cast technique and exposed to UV radiation with Bezoin Ethyl Ether (BEE) as photoinitiator. The addition of MC into SPEEK polymer enhances the conductivity up to 8.7 × 10−3 Scm−1 at 30 °C temperature and 80% re...
Article
Full-text available
Effect of glucose loading on the synthesis mesoporous carbon had been studied using hard template method where mesoporous silica SBA-15 was used as a template. To obtain a large pore of mesoporous carbon sample, a large pore of silica template was used. A series of mesoporous carbon sample was synthesized by loading different amounts of glucose (2....