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Dual-electrocatalysis behavior of star-like zinc-cobalt-sulfide decorated with cobalt-molybdenum-phosphide in hydrogen and oxygen evolution reactions
, Article Nanoscale ; Volume 13, Issue 41 , 2021 , Pages 17576-17591 ; 20403364 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Royal Society of Chemistry
2021
Abstract
Although important advances have been acquired in the field of electrocatalysis, the design and fabrication of highly efficient and stable non-noble earth-abundant metal catalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) remain a significant challenge. In this study, we have designed a superior bifunctional catalyst for OER and HER in alkaline media based on the Co-Mo-P/Zn-Co-S multicomponent heterostructure. The as-prepared multicomponent heterostructure was successfully obtained via a simple three-step hydrothermal-sulfidation-electrodeposition process consisting of star-like Co-Zn-S covered with Co-Mo-P. The structure and morphology evaluation of the...
Beyond hierarchical mixed nickel-cobalt hydroxide and ferric oxide formation onto the green carbons for energy storage applications
, Article Journal of Colloid and Interface Science ; Volume 593 , 2021 , Pages 182-195 ; 00219797 (ISSN) ; Hekmat, F ; Shahrokhian, S ; Sharif University of Technology
Academic Press Inc
2021
Abstract
To attain superior energy density concurrently with high power density, high-performance supercapacitors have been developed. Herein an innovative strategy has been adopted to fabricate unique binder-free electrodes composed of a unique porous structure of binary metal carbonate hydroxide nanomace-decorated hydrothermal porous carbon spheres (PCSs). Hierarchical nickel-cobalt carbonate hydroxide (NiCOCH) nanomaces, directly grown on PCSs, are used as positive electrodes for supercapacitors fabrication. Furthermore, Fe2O3@PCS composites, having benefits of highly reversible redox reaction in the negative potential window and highly porous structure, are employed as the negative electrode in...
A Study on Optoelectronic Properties of Copper Zinc Tin Sulfur Selenide: A Promising Thin-Film Material for Next Generation Solar Technology
, Article Crystal Research and Technology ; Volume 56, Issue 7 , 2021 ; 02321300 (ISSN) ; Zubair, M ; Khesro, A ; Ahmed, R ; Uddin, S ; Shahzad, N ; Alrobei, H ; Kalam, A ; Al-Sehemi, A. G ; Ul Haq, B ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe...
Beyond hierarchical mixed nickel-cobalt hydroxide and ferric oxide formation onto the green carbons for energy storage applications
, Article Journal of Colloid and Interface Science ; Volume 593 , 2021 , Pages 182-195 ; 00219797 (ISSN) ; Hekmat, F ; Shahrokhian, S ; Sharif University of Technology
Academic Press Inc
2021
Abstract
To attain superior energy density concurrently with high power density, high-performance supercapacitors have been developed. Herein an innovative strategy has been adopted to fabricate unique binder-free electrodes composed of a unique porous structure of binary metal carbonate hydroxide nanomace-decorated hydrothermal porous carbon spheres (PCSs). Hierarchical nickel-cobalt carbonate hydroxide (NiCOCH) nanomaces, directly grown on PCSs, are used as positive electrodes for supercapacitors fabrication. Furthermore, Fe2O3@PCS composites, having benefits of highly reversible redox reaction in the negative potential window and highly porous structure, are employed as the negative electrode in...
A study on optoelectronic properties of copper zinc tin sulfur selenide: A promising thin-film material for next generation solar technology
, Article Crystal Research and Technology ; Volume 56, Issue 7 , 2021 ; 02321300 (ISSN) ; Zubair, M ; Khesro, A ; Ahmed, R ; Uddin, S ; Shahzad, N ; Alrobei, H ; Kalam, A ; Al Sehemi, A. G ; Ul Haq, B ; Sharif University of Technology
John Wiley and Sons Inc
2021
Abstract
Studies on copper zinc tin sulpher selenide (CZTSSe) thin-film material and its applications as a base material are intensively being researched since it is an earth-abundant, inexpensive, flexible, and interesting material for next-generation optoelectronic technologies. Apropos, this study explores and reports the synthesis of CZTSSe thin films and their key optoelectronics characteristics. The reported films are fabricated on a soda-lime glass substrate by using a physical vapor deposition technique, and then annealed from 250 to 450 °C. From the X-ray diffraction analysis, the structure of the as-deposited thin films is found to be amorphous in nature. Annealed thin films of CZTSSe...
Facile deposition of porous fluorine doped tin oxide by Dr. blade method for capacitive applications
, Article Ceramics International ; Volume 47, Issue 4 , 2021 , Pages 5487-5494 ; 02728842 (ISSN) ; Tajabadi, F ; Dastan, D ; Sangpour, P ; Shi, Z ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Three-dimensional macroporous fluorine-doped tin oxide (p-FTO) films were successfully deposited using commercial ink of FTO powder and SnCl2 salt via Dr. Blade method. Various features of p-FTO thin films were studied as a function of the ink composition and sintering temperature. The morphological studies corroborated formation of porous, uniform, and crack-free FTO films after annealing at 300 °C for 10 min in air. X-ray diffraction pattern demonstrated development of highly crystalline FTO films. The lowest sheet resistance of 47 Ω/□ was obtained for the p-FTO film with a thickness of 21 μm. The capacitance of thin p-FTO films was investigated using a three-electrode system and the...
Facile synthesis of highly efficient bifunctional electrocatalyst by vanadium oxysulfide spheres on cobalt-cobalt sulfonitride nanosheets for oxygen and hydrogen evolution reaction
, Article Electrochimica Acta ; Volume 391 , 2021 ; 00134686 (ISSN) ; Esfandiar, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Synthesis of efficient, low-cost, and stable bifunctional electrocatalysts with earth-abundant resources for electrochemical water electrolysis is a challenging subject for large-scale energy conversion processes. Herein, we report a high-performance electrocatalyst based on vanadium oxysulfide/cobalt-cobalt sulfonitride (VOS/Co-CoSN) for oxygen and hydrogen evolution reaction (OER and HER). The Co-CoSN film was synthesized on a copper sheet (CS) by a facile electrodeposition method. Then, VOS was electrochemically grown onto the Co-CoSN@CS electrode at various deposition times. At the optimal deposition time (300 s), the obtained VOS-300/Co-CoSN catalyst was studied for OER and HER in...
A single layer deposition of Li-doped mesoporous TiO2beads for low-cost and efficient dye-sensitized solar cells
, Article New Journal of Chemistry ; Volume 45, Issue 5 , 2021 , Pages 2470-2477 ; 11440546 (ISSN) ; Nouri, E ; Mohsenzadegan, N ; Mohammadi, M. R ; Martinez Chapa, S. O ; Sharif University of Technology
Royal Society of Chemistry
2021
Abstract
Herein, we report a new strategy for improving the efficiency and reducing the fabrication cost of dye-sensitized solar cells (DSCs) by elimination of the three- or four-fold layer deposition of TiO2. This is performed by replacing a single layer deposition of mesoporous TiO2 beads, with sub-micrometer size, high surface area and tunable pore size, synthesized by a combination of sol-gel and solvothermal methods. Furthermore, superior electronic properties gained by a reduction in electronic trap states are achieved through doping of pristine TiO2 beads with lithium. The beads have a spherical shape with monodispersed texture consisting of anatase-TiO2 nanocrystals and ultra-fine pores. The...
Network-constrained optimal scheduling of multi-carrier residential energy systems: a chance-constrained approach
, Article IEEE Access ; Volume 9 , 2021 , Pages 86369-86381 ; 21693536 (ISSN) ; Ranjbar, H ; Shafie Khah, M ; Ehsan, M ; Catalão, J. P. S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
This paper presents a day-ahead scheduling approach for a multi-carrier residential energy system (MRES) including distributed energy resources (DERs). The main objective of the proposed scheduling approach is the minimization of the total costs of an MRES consisting of both electricity and gas energy carriers. The proposed model considers both electrical and natural gas distribution networks, DER technologies including renewable energy resources, energy storage systems (ESSs), and combined heat and power. The uncertainties pertinent to the demand and generated power of renewable resources are modeled using the chance-constrained approach. The proposed model is applied on the IEEE 33-bus...
Aqueous spray pyrolysis of CuInSe2 thin films: Study of different indium salts in precursor solution on physical and electrical properties of sprayed thin films
, Article Materials Science in Semiconductor Processing ; Volume 126 , 2021 ; 13698001 (ISSN) ; Bagher Ghorashi, S. M ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Herein, we deposited CuInSe2(CISe) thin films by using aqueous spray deposition method and post selenization process. The effect of different indium precursor salts including indium chloride, indium nitrate and indium acetate on the structural, morphological, optical and electrical properties of sprayed CISe layers has been studied by using x-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM-EDS), optical transmission (UV–Vis), Mott-Schottky analysis, I–V dark measurements. Although all the deposited thin films show a chalcopyrite tetragonal ordering structure of CISe, the crystallinity, morphology, and electrical characteristics are strongly influenced by the type of...
Optoelectrical and structural characterization of Cu2SnS3 thin films grown via spray pyrolysis using stable molecular ink
, Article Solar Energy ; Volume 224 , 2021 , Pages 218-229 ; 0038092X (ISSN) ; Gharabeiki, S ; Mahdavi, S. M ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
This work focused on the spray pyrolysis deposition of Cu2SnS3 (CTS) thin films using a stable basic solution. The effect of the most important parameters including the substrate temperature and copper concentration on the structural, optical and electrical properties of as-deposited thin films was investigated. Qualified thin films with suitable microstructure and composition could be deposited at 370℃. XRD and Raman analysis while confirming the pure CTS film formation, show that as the Cu/Sn decreases, the crystal structure layers are changed from the tetragonal phase to the cubic phase mixed with Sn-rich phases. The optical study shows its band gap between 1.08 and 1.2 eV for different...
CVD growth of the nanostructured Ni3S2 thin films as efficient electrocatalyst for hydrogen evolution reaction
, Article Vacuum ; Volume 188 , June , 2021 ; 0042207X (ISSN) ; Moradlou, O ; Moshfegh, A. Z ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The development of low cost and earth abundant electrocatalyst with high performance and desirable stability for hydrogen evolution reaction (HER) is an important issue in energy applications. Nickel sulfide thin films (NiSx) are formed on conductive nickel foam substrates via chemical vapor deposition (CVD) at 300 °C under low pressure condition. A single phase of Ni3S2 was produced by controlling the ratio of precursors. X-ray diffraction (XRD), field emission scanning electron spectroscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements were conducted to characterize and compare properties of the samples. According to XRD and XPS data analysis, the growth...
The effect of target annealing temperature on optical and structural properties and composition of CdS thin films prepared by pulsed laser
, Article Optical Materials ; Volume 27, Issue 10 , 2005 , Pages 1583-1586 ; 09253467 (ISSN) ; Iraji Zad, A ; Tilaki, R. M ; Sharif University of Technology
Elsevier
2005
Abstract
We studied the effect of target annealing temperature on optical and structural properties and composition of CdS thin films prepared by pulsed Nd:YAG laser. Deposited samples from annealed targets at 300 °C showed a mixed cubic and hexagonal structure, a band gap of about 2.56 eV and Cd/S ratio equal 1. This ratio increased to 2.40 and its band gap decreased to 2.46 eV when the sample was annealed at 500 °C for 1 h in air. However, films prepared from annealed targets at 500 °C became dark due to existence of polymorphous phase of CdO. Films changed to transparent yellow color with a hexagonal CdS structure and some peaks related to CdO after annealing above 250 °C in air. Its band gap...
Adaptive modeling of powder deposition for control and monitoring application
, Article DETC2005: ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Long Beach, CA, 24 September 2005 through 28 September 2005 ; Volume 1 A , 2005 , Pages 755-760 ; 0791847381 (ISBN) ; Fathi, A ; Khajepour, A ; Toyserkani, E ; Sharif University of Technology
2005
Abstract
Laser Powder Deposition technique is an advanced production method with many applications. Despite this fact, reliable and accurate control schemes have not yet fully developed for this method. This article presents method for in time identification of the process for modeling and adaptation of proper control strategy. ARMAX structure is chosen for system model. Recursive least square method and Kalman Filter methods are adopted for system identification, and their performance are compared. Experimental data was used for system identification, and proper filtering schemes are devised here for noise elimination and increased estimation results. It was concluded that although both methods...
A kinetic study on the electrodeposition of cadmium with the presence of organic agents in sulfate solutions
, Article Materials Chemistry and Physics ; Volume 94, Issue 1 , 2005 , Pages 23-28 ; 02540584 (ISSN) ; Afshar, A ; Ghasemi, H ; Sharif University of Technology
2005
Abstract
The electrodeposition of cadmium is studied by electrochemical techniques with the presence of the organic agents. The cyclic voltammetry results clearly show that the electrodeposition of cadmium is a diffusion-controlled process associated with a typical nucleation process. With addition of the thiourea, 3-Picolin and benzyl alcohol organic agents simultaneously in sulfate solution, the redox potential of cadmium is shifted to more negative potentials. In this case, the current transients reveal an instantaneous nucleation with a typical three-dimensional (3D) growth mechanism, while it shows progressive nucleation mechanism without the ternary-species organic agents. In addition, the...
Binary and ternary NiTi-based shape memory films deposited by simultaneous sputter deposition from elemental targets
, Article Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films ; Volume 23, Issue 5 , 2005 , Pages 1425-1429 ; 07342101 (ISSN) ; Cao, Y. Z ; Sadrnezhaad, S. K ; Barber, Z. H ; Sharif University of Technology
2005
Abstract
The most challenging requirement for depositing NiTi-based shape memory thin films is the control of film composition because a small deviation can strongly shift the transformation temperatures. This article presents a technique to control film composition via adjustment of the power supplied to the targets during simultaneous sputter deposition from separate Ni, Ti, and X (e.g., Hf) targets. After optimization of sputter parameters such as working gas pressure, target-substrate distance, and target power ratio, binary Ni100-x Tix thin films were fabricated and characterized by energy dispersive x-ray spectroscopy in a scanning electron microscope (to measure the film composition and...
From continuous to quantized charging response of silicon nanocrystals obtained by ultra-low energy ion implantation
, Article Solid-State Electronics ; Volume 49, Issue 7 , 2005 , Pages 1198-1205 ; 00381101 (ISSN) ; Grisolia, J ; Ben Assayag, G ; Coffin, H ; Atarodi, S. M ; Claverie, A ; Sharif University of Technology
2005
Abstract
In this paper, we present a study on the contribution of silicon nanocrystals to the electrical transport characteristics of large (100 μm × 100 μm) and small (100 nm × 100 nm) metal-oxide-semiconductor (MOS) capacitors at room temperature. A layer of silicon nanocrystals is synthesized within the oxide of these capacitors by ultra-low energy ion implantation and annealing. Several features including negative differential resistance (NDR), sharp current peaks and random telegraph signal (RTS) are demonstrated in the current-voltage and current-time characteristics of these capacitors. These features have been associated to charge storage in silicon nanocrystals and to the resulting Coulomb...
Multi-target sputter deposition of Ni50Ti 50 - XHfx shape memory thin films for high temperature microactuator application
, Article Sensors and Actuators, A: Physical ; Volume 121, Issue 2 , 2005 , Pages 543-548 ; 09244247 (ISSN) ; Cao, Y. Z ; Barber, Z. H ; Sharif University of Technology
2005
Abstract
High temperature shape memory NiTiHf thin films with varying hafnium contents up to 28.7 at.% were fabricated by DC magnetron sputtering using simultaneous sputter deposition from separate elemental targets. The required film composition was achieved by adjusting the power ratio to the targets. The as-deposited films were amorphous; a post deposition annealing was performed at 550 °C to crystallize the films. Two-micron thick films were characterized by energy dispersive spectroscopy in a scanning electron microscope, temperature controlled X-ray diffraction, differential scanning calorimetry, and atomic force microscopy. The results showed that above 10 at.% Hf additions the transformation...
Co surface modification by bias sputtering in Cu/Co(Vb)/NiO/ Si(100) magnetic multilayer structures
, Article Physica Status Solidi C: Conferences ; Volume 1, Issue 7 , 2004 , Pages 1744-1747 ; 16101634 (ISSN) ; Sangpour, P ; Sharif University of Technology
2004
Abstract
To investigate the Ta/Co/Cu/Co/NiO/Si(100) spin valve structure, fabrication and characterization of the Cu/Co/NiO/Si(100) system was studied for further understanding the structure. The system was grown by employing combinative DC sputtering-evaporation technique. Nickel oxide with a thickness of about 30 nm was deposited on Si(100) substrate using thermal evaporation technique.The cobalt film, then, with a thickness of about 3 nm was grown by DC sputtering under various applied negative bias voltages ranging from 0 to - 80 V. The optimum bias voltage (Vb = -60 V) for the growth of Co layer was determined by atomic force microscopy (AFM), four-point probe sheet measurement (Rs) and scanning...
Oscillator strength calculations in color centers of diamond and the role of spin
, Article European Physical Journal B ; Volume 39, Issue 4 , 2004 , Pages 441-446 ; 14346028 (ISSN) ; Vesaghi, M. A ; Esfarjani, K ; Sharif University of Technology
2004
Abstract
A generalized Hubbard model based on a molecular approach is used to calculate many electron wavefunctions of diamond vacancies. We have calculated the oscillator strength of the dipole transition rates from the ground states of the neutral and negatively charged vacancies. The ratio of the oscillator strengths is in very good quantitative agreement with the reported optical spectroscopic data. Electronic configurations in the ground and dipole allowed excited states are presented. With the proposed picture, the much larger oscillator strength of the negatively charged vacancy with respect to other experimentally investigated color centers N-V, H3, X3 and H4 is explained