Nazirul Nazrin Shahrol Nidzam

Bio: Nazirul Nazrin Shahrol Nidzam is an academic researcher from Universiti Putra Malaysia. The author has contributed to research in topics: Materials science & Infrared spectroscopy. The author has an hindex of 1, co-authored 5 publications receiving 7 citations.

Structural stability and electronic properties of graphene/germanene heterobilayer

Abstract: In this work, the structural and electronic properties of graphene/germanene heterobilayer is investigated by using density functional theory. We find that the graphene and germanene are bounded together mainly by weak van der Waal forces. This is supported by small interlayer binding energy of graphene/germanene heterobilayer. In the heterobilayer, the Dirac cone characteristics of both graphene and germanene layers are well preserved. The band gap opening is found due to the unsaturated pz-orbital of germanene layer. Further variation of compressive strain along the normal of the heterobilayer increases the band gap opening in the heterobilayer. Inhomogeneous charge redistribution is found in between graphene and germanene layer, where small charge accumulation region is found in germanene layer while charge depletion region in graphene layer. The total charge accumulations in between graphene and germanene sheets is 5.645 × 10−4 e .

Fabrication of binary (ZnO) x (TiO 2 ) 1−x nanoparticles via thermal treatment route and evaluating the impact of various molar concentrations on the structure and optical behaviors

Abstract: Numerous studies have explored the behaviors of ZnO–TiO2 nanoparticles resulting through various routes of fabrication. To date, the utilization of thermal treatment method to convey ZnO–TiO2 nanoparticles has never been considered. In the present study, binary (ZnO)x(TiO2)1−x NPs were effectively blended by using thermal treatment technique. Zinc nitrate and titanium(IV) propoxide with polyvinylpyrrolidone, PVP, were utilized to set up the samples. Energy-dispersive X-ray (EDX) spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction (XRD) spectroscopy, ultraviolet–visible (UV–Vis) spectrophotometer transmission electron microscopy (TEM) and photoluminescence spectroscopy were utilized to examine the impact of changing the molar proportion to the structure and optical features of (ZnO)x(TiO2)1−x NPs. The XRD spectra revealed that after calcination, the amorphous sample had transformed into crystalline nanoparticles. The prepared (ZnO)x(TiO2)1−x NPs average diameter was around 25.922–28.531 nm according to TEM analysis. The analyzation of UV–Vis spectroscopy determined the optical measurements parameters including the energy gap and Urbach energy of binary (ZnO)x(TiO2)1−x NPs. The optical energy gap varied in the range of 3.2496–3.2863 eV as the molar ratio increases from x = 0.24 to x = 0.72. The enhancement within the nanoparticles optical properties suggests a good potential for photocatalysis application.

Comparison Study of Elastic, Physical and Structural Properties for Strontium Oxide and Manganese Oxide in Borotellurite Glasses for High Strength Glass Application

Abstract: In this research, the study of two dopants, strontium oxide and manganese oxide were thoroughly investigated based on the elastic properties for the purpose of high strength glass application. The melt quenching technique method was used to synthesize two series of borotellurite glass systems doped with manganese and strontium. Elastic measurement, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the prepared glass samples. The increment of molar volume confirmed the theory that molar volume is inversely proportional to the density parameters. A broad hump was observed during XRD as the samples shows pure amorphous nature. In FTIR, the vibrations of the functional group of the tellurite network were recorded such as TeO4 trigonal bipyramids and TeO3 trigonal pyramids, by addition of both dopants. On the other hand, ultrasonic velocity was used to determine the elastic moduli of the glass such as bulk modulus, shear modulus, longitudinal modulus, Young’s Modulus, microhardness and Poisson’s ratio which showed decreasing and increasing trends with the increased concentration of MnO2 and SrO respectively. It is also inferred that strontium oxide has better elastic properties than manganese oxide.

Stability and Electronic Properties of Two-Dimensional Silicene and Germanene on Graphene

Abstract: We present first-principles calculations of silicene/graphene and germanene/graphene bilayers. Various supercell models are constructed in the calculations in order to reduce the strain of the lattice-mismatched bilayer systems. Our energetics analysis and electronic structure results suggest that graphene can be used as a substrate to synthesize monolayer silicene and germanene. Multiple phases of single crystalline silicene and germanene with different orientations relative to the substrate could coexist at room temperature. The weak interaction between the overlayer and the substrate preserves the low-buckled structure of silicene and germanene, as well as their linear energy bands. The gap induced by breaking the sublattice symmetry in silicene on graphene can be up to 57 meV.

Nanofabrication of (Cr2O3)x (NiO)1-x and the impact of precursor concentrations on nanoparticles conduct

Abstract: This study aims to synthesize the (Cr2O3)x (NiO)1-x nanoparticles at lower and higher precursor values using the calcination method. There is a lack in regard to investigating the lower and higher precursor values on structural and optical properties of the (Cr2O3)x (NiO)1-x nanoparticles. To synthesize the (Cr2O3)x (NiO)1-x nanoparticles, Cr (III) acetate hydrate and Ni (II) acetate tetrahydrate were reacted with poly (vinyl alcohol). Several techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR), have been employed to characterize the synthesized sample. The XRD pattern analysis indicated that, following calcination, nanoparticle formation occurred, indicating hexagonal crystalline structures (HCP) and face-centred cubic (FCC) of (Cr2O3)x (NiO)1-x nanoparticles. FT-IR verified the existence of Ni–O and Cr–O as the original compounds of ready (Cr2O3)x (NiO)1-x nanoparticle samples. In term of average particle size, this varied from 5 to 16 nm when the precursor concentration rised from x = 0.20 to x = 0.80, as reflected in the TEM results. X-ray photoelectron spectroscopy (XPS) was employed to measure the valence state and surface composition of the prepared product nanoparticles. To identify the optical band gap using the Kubelka–Munk equation, diffuse UV–visible reflectance spectra were employed, which revealed that the energy band gap fell with a rise in the value of x. In addition, photoluminescence (PL) spectra indicated that the photoluminescence intensity was related to a directly proportional way to particle size. Hence, the results can be employed with a broad range of applications in solar cell energy applications at higher x values and antibacterial activity at lower x values.

Comparative Study of Zn2Ti3O8 and ZnTiO3 Photocatalytic Properties for Hydrogen Production

Abstract: In the present work, zinc titanates (ZTO) as photocatalysts were synthesized, characterized, and evaluated aiming to study their photocatalytic properties for hydrogen production under visible-light irradiation and employing MeOH (methanol) and TEOA (Triethanolamine) as sacrificial agents. ZTO were synthesized by modified Pechini method. Characterization of materials consisted in TGA, XRD, TEM, EELS, BET, and UV–Vis. Surface interaction studies consisted of FT-IR spectroscopy and determination of MeOH and TEOA adsorption–desorption capacities on the ZTO by TGA. Zinc titanates were evaluated as photocatalyst for H2 production using an artificial visible light and monitored by GC. TGA results led to establish calcination temperatures of 550 °C (Zn2Ti3O8) and 700 °C (ZnTiO3) to reach their crystalline phases. XRD analysis of sample cds-ZTO found cubic Zn2Ti3O8 and traces of the ZnO crystalline phase, while p-ZTO exhibited a mixture of cubic and hexagonal ZnTiO3 crystalline phases. Surface area for cds-ZTO was 88 m2/g, while ZnTiO3 had 13 m2/g. Photocatalytic H2 production for cds-ZTO and p-ZTO using TEOA as sacrificial agent showed the highest photocatalytic activities generating 548 and 441 µmolH2/h.gcat. TEOA adsorption–desorption capacity was found superior on cds-ZTO and p-ZTO than that for MeOH on both samples.