Ali Asghar Sabbagh Alvani

Amirkabir University of Technology | TUS · Color & Polymer Research Center (CPRC)

We designed and fabricated a photocatalyst made of reduced titanium dioxide nanorods (TiO2-x NRs) that incorporates silver nanoparticles (Ag NPs) and reduced graphene oxide (rGO) sheets, to narrow the band...

We report the influence of pH on the hydrothermal growth of TiO2 nanostructures, observing variations in photocatalytic activity. Using comprehensive characterization techniques, we find that nanorod growth significantly depends on the synthesis conditions and that TiO2 mainly crystallizes in the rutile phase. A red shift in the absorption edge tow...

Controllable synthesis of Metal‐organic frameworks (MOFs) with well‐defined morphology, composition and size is of great importance towards understanding their structure‐property relationship in various applications. Herein, the effect of morphology of photocatalysts on their optical behavior and photocatalytic efficiency was identified utilizing p...

Controllable synthesis of Metal-organic frameworks (MOFs) with well-defined morphology, composition and size is of great importance towards understanding their structure-property relationship in various applications. Herein, the effect of morphology of photocatalysts on their optical behavior and photocatalytic efficiency was identified utilizing p...

We report the design and one-pot synthesis of Ag-doped BiVO4 embedded in reduced graphene oxide (BiVO4:Ag/rGO) nanocomposites via a hydrothermal processing route. The ternary heterojunction photocatalysts exhibited high efficiency for visible light degradation of model dyes and were correspondingly used for the preparation of photocatalytic membran...

We report the synthesis and characterization of CuWO4, its functionalization with plasmonic Ag nanostructures, and its photoelectrochemical properties. First, a solution-phase polyvinylpyrrolidone (PVP)-assisted approach was used to prepare shape-controlled plasmonic Ag (nanoparticles (NPs) and nanowires (NWs)) via heterogeneous nucleation. The gro...

Purpose Over the past decades, intense efforts have been devoted to design and synthesize efficient photocatalysts which are active under sunlight for environmental and energy applications. Titanium dioxide (TiO 2 ) has attracted much attention over many years for organic contaminant degradation in air or water due to its strong optical absorptivit...

Costly and time-consuming recovery of photocatalysts from treated water is one of the main challenges for the photocatalysis process. In this regard, an Ag-functionalized Bi2W(Mo)O6 photocatalyst was successfully synthesized via a cetyltrimethylammonium bromide (CTAB)-assisted hydrothermal method, immobilized on a polyvinylidene fluoride (PVDF) mem...

Hydrogenated TiO2 nanorods (H-TNRs) were hydrothermally prepared in presence of H2/N2 gas flow resulting in higher visible-light photoactivity. This H-TNR could be adopted as a promising photocatalyst for energy conversion.

We report the fabrication and characterization of molybdenum (Mo)-doped ZnV2O6/reduced graphene oxide (rGO) composite and its use as photoanode for photoelectrochemical (PEC) hydrogen production. Compared to pure ZnV2O6, Mo ions act as electron donor in the ZnV2O6:Mo lattice increasing charge carrier concentration and subsequently mobility in the b...

This study describes photophysical properties of pure and Ag-doped BiVO 4 nanocrystals. Diffuse reflectance spectroscopy illustrated that the absorption of BiVO 4 :Ag increases due to prolong and suppress electron-hole pair recombination.

Water-based polyurethane coatings give a soft feeling for surface engineering for advanced wear- and friction-resisted purposes. In this work, we synthesized three types of polyols from castor oil applying short- and high-efficiency method for potential soft coating uses, as an appropriate alternative for methods that use a rotary evaporation and a...

Nanostructured hydroxyapatite (HA) is a new class of biocompatible fillers which has been recently utilized in bio hybrid materials by virtue of its excellent tissue bioactivity and biocompatibility. However, the need for higher thermal stability, solubility, surface bioactivity, radiopacity, and remineralization ability suggests a divalent cation...

A castor oil-based fatliquoring agent for use in leather coating was prepared via Pickering emulsions stabilized by metal–organic frameworks (MOFs). The partially oxidized ZIF-8 (POZIF-8) nanoparticles were used as MOF in the presence of a castor oil-based dispersant. The results of the stability test showed that the presence of POZIF-8 nanoparticl...

The first-principles calculations based on density functional theory with generalized gradient approximation were carried out to investigate the fundamental features of hydroxyapatite, the primary constituent of human bone and tooth, for use in light-curable dental composites. Moreover, the influence of strontium incorporation into hydroxyapatite o...

In this study, three sorts of polyols were successfully synthesized from castor oil using a Dean-Stark quick, eco-friendly and high-efficiency method. For this purpose, castor oil was epoxidized in the presence of two types of catalysts including γ-alumina and formic acid, named as ECO Al and ECO F , respectively. Epoxidized castor oils were then c...

Ag-functionalized CuWO4/WO3 heterostructures were successfully prepared via a polyvinyl pyrrolidone (PVP)-assisted sol-gel (PSG) route. Thin films prepared by electrophoretic deposition were used as photoanodes for photoelectrochemical (PEC) water splitting. Compared to pristine CuWO4 and WO3 films, a significant enhancement of the photocurrent (3-...

A new plasmonic Ag hybridized CuWO4/WO3 heterostructure was successfully synthesized via ligand-assisted sol gel method. The as-prepared plasmonic nanohybrid was thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, photoluminescence (PL) spectrometry, X-ray photoelectron spectroscopy (XPS...

A nanocomposite of ZnV2O6 with hierarchical flower-like structure hybridized with reduced graphene oxide (rGO) was fabricated using a facile hydrothermal approach. The structure, morphology, optical and electronic properties were explored using comprehensive analytical techniques. The results revealed that the rGO sheets were decorated with the in...

Chalcostibite copper antimony sulfide (CuSbS2) is a promising candidate for application in solar cells. The functionality of CuSbS2 –particles depends on particle size and morphology, and controlling of these two parameters during synthesis process is of uttermost importance. In this work, CuSbS2 particles were prepared by a facile heat-up synthesi...

We used first principles calculations based on density functional theory with generalized gradient approximation to investigate and compare the structural, electronic and optical properties of two photoanode materials, ZnV2O6 and Zn2V2O7, for use in photocatalytic water splitting. After geometry optimization, the calculated structural parameters ev...

Single crystalline platelet chalcostibite (CuSbS2) particles with good shape and size uniformity were successfully prepared using a hot injection method. In this synthesis, sulfur powder in oleylamine (OLA) was employed as a sulfonating agent. The synthesized CuSbS2 had an orthorhombic structure with a plate-like morphology. Selected area electron...

Chalcostibite copper antimony sulfide (CuSbS2) micro- and nanoparticles with a different shape and size have been prepared by a new approach to hot injection route. In this method, sulfur in oleylamine (OLA) is employed as a sulfonating agent providing a simple route to control the shape and size of the particles, which enables the optimization of...

In this research, a systematic study has been directed to evaluate epoxy matrix nanocomposite performance of Al2O3 nanoparticles incorporated into epoxy resin. An ultrasonic mixing process was utilized to achieve homogenous dispersion of these nanoparticles into epoxy resin. Several mechanical and tribological tests, such as three-point bending tes...

We believe that reduced graphene oxide sheets can promote the photogenerated charge separation and electron transport in photoanodes for O2 evolution in photoelectrochemical cells because of their unique 2D carbon structure

one-dimensional TiO2 nanorods were synthesized via hydrothermal method at different pH for solid state perovskite sensitized solar cells and various structural and optical characteristics were analysed by XRD, SEM and UV-visible spectroscopy.

CH3NH3PbI3 and other Pb-based organic-inorganic perovskites, are new class of light absorbers in different kind of solar cells. In comparison with lead-based perovskites, there are just a few papers about lead-free perovskites; so in this work nontoxic Sn-based perovskites were chosen and synthesized by solution method in different annealing temper...

As the energy demand of the world increases, we need to find and replace a renewable energy resources, like solar energy with fossil fuels. Different kind of solar cells are introduced to use this energy. Dye sensitized solar cells are an important class of solar cells in which the dye absorbs the solar light. In this review, metal-based and metal-...

We report an advanced method for the self-organization of an optomagnetic nanocomposite composed of both fluorescent clusters (ZnS quantum dots, QDs) and magnetic nanoparticles (CoFe2O4). ZnS nanocrystals were prepared via an aqueous method at different temperatures (25, 50, 75, and 100 °C). Their structural, optical and chemical properties were com...

A series of near-infrared reflective nano-pigments based on Co1−xZnxCr2−yAlyO4 (x = 0-1 and y = 0-2) have been synthesized via Pechini-type sol-gel method. Comprehensive analyses were carried out to characterize the resulting powders including X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared analysis and UV...

The present study reports the performance of a new photosensitizer -AgI quantum dots (QDs)- and mesoporous titania (TiO2) nanocrystals synthesized by sol-gel (SG) method for solar cells. Furthermore, the effects of n-heptane on the textural properties of TiO2 nanocrystals were comprehensively investigated by X-ray diffraction (XRD), Fourier transfo...

ZnS QDs were synthesized via aqueous method and growth process of crystals were kinetically studied. PL Results revealed that the growth kinetic involves two steps in which Oriented Attachment and Ostwald Ripening are dominated mechanism.

In the present study, the ZnS semiconductor quantum dots were successfully ‎synthesized via an aqueous method utilizing glutathione (GSH), thioglycolic acid (TGA) and ‎polyvinyl pyrrolidone (PVP) as capping agents. The structural, morphological and photo-‎physical properties and biocompatibility were investigated using comprehensive ‎characterizati...

The most effective process parameters were determined to synthesize spherical LaF3 nanoparticles with controllable size based on ethylenediaminetetraacetic acid (EDTA) via co-precipitation technique. Thermogravimetricdifferential thermal analysis, X-ray diffraction, scanning electron microscopy, dynamic light scattering and FT-IR spectroscopy were...

We report on the photovoltaic performance of AgI quantum dots sensitized solar cells. The assembled solar cells yielded a power conversion efficiency of 0.64% and a short-circuit current of 2.13 mA/cm2 under one sun illumination.

Hexagonal pure LaF3 and Yb/Er, Yb/Ho co-doped LaF3 nanostructures have been successfully synthesized via an efficient, environmentally mild hydrothermal route and the up-conversion luminescence properties were comprehensively investigated for photovoltaic devices such as solar cells.

In this research, a new blue-emitting nanocrystalline phosphor, SrZn2Si2O7: Eu2+, utilizable in InGaN LEDs, was successfully synthesized via two routes: the sol-gel method (SG) and solid-state reaction (SS). The effects of the preparation processes on the crystallization, morphology and thermal properties were analyzed by appropriate techniques, su...

Ce-doped FeVO4 nanocomposites were successfully synthesized using reverse micro-emulsion route. Thermal and microstructural characteristics were comprehensively investigated by simultaneous thermal analysis, X-ray diffraction (XRD), scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spect...

A series of emission-tunable nanophosphors with nominal composition of Sr 0.96 Zn 2 − x Si 2 O 7 : 0.04 Eu 2 + , x Mn 2 + ( 0 ≤ x ≤ 0.15 ) were designed and synthesized by solgel technique for application in white-light-emitting diodes. The structural, morphological, and optical properties were investigated using comprehensive characterization meth...

ZnO quantum dots (QDs) were successfully synthesized via the precipitation technique, and the effect of the Mn2+ ion concentration as dopant on the optical properties was studied. In order to control the particle size by limiting the growth of the particles after the nucleation and to provide a side group on the surface, which can be further conjug...

In classical mechanics, based on the generalized Hook's law, stress is only a function of strain. However, in the strain gradient theory, stress is not only a function of strain, but also a function of high-order gradients of strain. This relationship between stress and strain and its new boundary conditions is derived using the principle of minimu...

The effects of the synthesis techniques: sol–gel combustion (SG), hydrothermal (HT) and co-precipitation (CP) on the structure, homogeneity, morphology and magnetic properties of SrCo0.2Fe11.8O19 hexaferrite ceramics have methodically been explored by X-ray diffraction (XRD), laser particle analyzer, scanning electron microscopy (SEM) and vibrating...

Two supplementary approaches in terms of thermal degradation kinetics and Taguchi's experimental design were employed toward developing a design effort for intumescent coatings. A model intumescent system including ammonium polyphosphate (APP), pentaerythritol (PER), melamine (MEL), thermoplastic acrylic resin and liquid hydrocarbon resin was chose...

In this research, a new blue-emitting phosphor Eu2+-doped SrZn2Si2O7 was developed for white light-emitting diodes via the sol–gel process. Thermogravimetric-differential thermal analysis, X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM), and photoluminescence (PL) spectra were used to characterize the resulting phosph...

In this research, a new SrMgAl(2) SiO(7):Eu(2+) phosphor was synthesized via the sol-gel method. The phase-forming processes were studied by thermogravimetric-differential thermal analysis and X-ray diffraction technique. Scanning electron microscopy showed that there is uniform morphology and microstructure owing to the sol-gel route. Spectrophoto...

The sol–gel preparative method was employed to synthesize SrZn2Si2O7:Eu nanostructure phosphors for white-light emitting diodes. The effects of calcination temperature and atmosphere as two important process parameters on the structural, morphological and optical properties were investigated using comprehensive characterization methods such as X-ra...

The novel Eu2+-activated SrZn2Si2O7 phosphors were successfully prepared via the wet chemical method. Obtained phosphor is efficiently excited in the wavelength range of 340–400 nm which matches to a near UV (NUV) emitting InGaN chip and emits strong band blue light peaking at 481 nm due to 4f6 5d1(2D)→4f7(8S7/2) transition of Eu2+ ions which acts...

A novel nanostructure pigment of Eu2+ doped SrMgAl2SiO7 was prepared via the sol–gel route. The phase composition and condition of crystallites during heating were characterized by X-ray diffraction (XRD) analysis. Investigation of optical properties by spectrophotometer illustrated that under short ultraviolet excitation wavelength, the main emiss...

In this research, new SrMgAl2SiO7:Eu2+ phosphor was synthesized via sol-gel method. The phase-forming process and sol-gel reactions were studied by thermogravimetricdifferential thermal analysis and X-ray diffraction. The luminescent and morphological properties of this nanocrystal pigment have been systematically investigated. The main emission pe...

A pure Silicate host namely Sr2MgSi2O7 as a support for a long-lasting afterglow when dopped with rare-earth elements was sought after. To this end the process of obtaining firing temperatures of the above mentioned phase in normal condition was carried out using suggested wet and dry methods. The degree of purity obtained in these preparatory meth...

Sr2MgSi2O7 host doped with Eu, Dy ions with high brightness and long afterglow was prepared by sintering at high temperature under weak reductive atmosphere. The luminescent properties of this photoluminescent pigment have been systematically studied. The analytical results indicated that the co-doped Eu and Dy ions have little influence on the str...

Long afterglow Sr3MgSi2O8: Eu, Dy phosphor with high brightness was prepared by sintering at high temperature and weak reductive atmosphere. The luminescent properties of this photoluminescent pigment were studied systematically by investigating concentration effects. The analytical results indicated that the main emission peaks appear at 482 nm. T...