Search for: photoelectrochemicals
Total 103 records
A novel screen-printed TiO2 photoelectrochemical sensor for direct determination and reduction of hexavalent chromium, Article Electrochemistry Communications ; Volume 61 , 2015 , Pages 110-113 ; 13882481 (ISSN) ; Goh, G. K. L ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
Elsevier Inc 2015
A novel and simple photoelectrochemical (PEC) sensor to detect Cr(VI) based on screen-printed TiO2 modified with gold nanoparticles is presented. The proposed PEC sensor showed a very low detection limit (S/N = 3) of 0.004 μM, over a wide linear concentration range from 0.01 μM to 100 μM with a high sensitivity of 11.88 μA.μM-1 Cr(VI). Results also indicated good anti-interference and superb recovery in natural media application for Cr(VI) sensing
Article Surfaces and Interfaces ; 2021 ; 24680230 (ISSN) ; Naseri, N ; Sharif University of Technology
Elsevier B.V 2021
The necessity of research in food and nutrition and the emergence of diabetes mellitus call for fast and efficient glucose detection. Here, series of highly sensitive non-enzymatic photoelectrochemical glucose sensor based on engineered titanium dioxide nanotube arrays has been synthesized using a simple electrochemical approach to tune nanotubes morphology in a way that the highest sensitivity factor (525.5 µAmM−1cm−2) and saturation concentrations (0.18 mM) achieved in the photoelectrochemical sensor. The formation of oxygen-rich titanium oxide was confirmed by several techniques. Dependent on the growth condition, nanotube length changed from 1.9 to 8.4 µm while their inner diameter...
Controlled engineering of WS
Solar Energy Materials and Solar Cells
; Zhao, M
; Moradlou, O
; Samadi, M
; Sarikhani, N
; Wang, Q
; Zhang, H. L
; Moshfegh, A. Z
Sharif University of Technology
2 nanosheets-CdS nanoparticle heterojunction with enhanced photoelectrochemical activity
Abstract We report the well-controlled preparation of WS
2 nanosheets-CdS nanoparticle heterojunction for photoelectrochemical (PEC) water splitting application. The WS 2 nanosheets with an average thickness of ~5 nm and lateral dimensions of ~200 nm were synthesized via liquid phase exfoliation of bulk WS 2 in water/ethanol solution, followed by deposition onto ITO substrate via electrophoretic method. CdS nanoparticles were grown via facile successive ion layer absorption and reaction (SILAR) method. Using these two well-controlled methods, CdS/WS 2/ITO and WS 2/CdS/ITO systems were fabricated. The loading of WS 2 nanosheets was...
Article Materials Letters ; Volume 163 , 2016 , Pages 81-84 ; 0167577X (ISSN) ; Mohammad Pour, R ; Iraji Zad, A ; Sharif University of TEchnology
Here in this research, we report on surface engineering of bulk Cu2O photocathode thorough employing nanostructured materials. Nanorods (NRs) of copper oxide with average lengths of 150 nm have been synthesized by anodization of Cu foil in aqueous KOH electrolyte, followed by annealing treatment. Several heating processes were examined to reach pure Cu2O nanostructures and lastly the moderate annealing procedure at 700 °C under Ar gas flow resulted in pure Cu2O nanostructures, confirmed by XRD analysis. Surface modified nanorod/bulk Cu2O electrode was prepared by spin coating of sediments suspension of anodized drop on bulk Cu2O film fabricated through thermal oxidation method, followed by...
M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza
ZnO is a wide and direct band gap (3.37 eV) semiconducting material with a large exciton binding energy (60 meV). It has been extensively studied in the last few years owing to its potential applications in various fields such as surface acoustic wave devices (SAW), transparent electrode, solar cell windows, photovoltaic devices, gas sensors and photoelectrochemical cells. Recently, much attention has been paid to rare-earth (RE) doped ZnO for possible applications in visible emitting phosphors in displays, high power lasers, and other optoelectronic devices. In this thesis, initially ZnO thin films were deposited on glass and ITO substrates using sol-gel dip-coating method. Optical and...
Ph.D. Dissertation Sharif University of Technology ; Ghorbani, Mohammad ; Simchi, Abdolreza
An isopropanol supercritical reducing environment was prepared by fabricating a high temperature, high pressure autoclave, in order to make a hybridized structure of zinc oxide and graphene oxide, entitled as ZnO-G. In this novel structure, the oxygen acts as bridging element between zinc and carbon, that connects a wide band gap semiconductor to a narrow banded one. The hybridization mechanism is studied by FTIR analysis, and morphology is shown by FE-SEM. The micrographs obtained from the thin film show a stacked pile of ZnO-G disks, like a button, dispersed on a crack free layer. In addition, the crystallographic structure was revealed by comparing low angle X-ray diffraction patterns to...
Article RSC Advances ; Volume 6, Issue 52 , 2016 , Pages 46282-46290 ; 20462069 (ISSN) ; Tedadi, N ; Banazadeh, A ; Naseri, N ; Sharif University of Technology
Royal Society of Chemistry 2016
A series of reduced graphene oxide/ZnxCd1-xS (RGO/ZnxCd1-xS) nanocomposites (0 < x < 1) with different ratios of Zn/Cd were synthesized via a facile hydrothermal route under optimized experimental conditions and were carefully characterized by various techniques. Because very little is known about the morphology, specific surface area, and crystal phase effects of RGO/ZnxCd1-xS crystals on their photoresponsivity, field-emission scanning electron microscopy (FE-SEM), BET surface area analysis and X-ray diffraction (XRD) data were studied to investigate their effects on photoactivity. Based on the results, a crystal phase transition from a cubic phase in RGO/Zn0.9Cd0.1S to a hexagonal...
Fabrication and surface stochastic analysis of enhanced photoelectrochemical activity of a tuneable MoS2-CdS thin film heterojunction, Article RSC Advances ; Volume 6, Issue 20 , 2016 , Pages 16711-16719 ; 20462069 (ISSN) ; Ebrahimi, M ; Zhao, M ; Moradlou, O ; Samadi, M ; Bayat, A ; Zhang, H. L ; Moshfegh, A. Z ; Sharif University of Technology
Royal Society of Chemistry 2016
A very simple and well-controlled procedure was employed to prepare CdS nanoparticle/few-layer MoS2 nanosheet/Indium tin oxide (ITO) thin film heterostructures. To tune and fabricate the CdS/MoS2(t)/ITO thin films with various surface topographies, first electrophoretic deposition (EPD) was used to deposit MoS2 nanosheets on the ITO substrate under an optimized applied potential difference (8 V) for different deposition times (t) of 30, 60, 120 and 240 s. Then, CdS nanoparticles were deposited via a successive ion layer adsorption and reaction (SILAR) technique. The highest photo-current density of 285 μA cm-2 was measured for the CdS/MoS2(60 s)/ITO sample, which was about 2.3 times higher...
Article Polymers for Advanced Technologies ; Volume 27, Issue 3 , 2016 , Pages 358-365 ; 10427147 (ISSN) ; Latifi, M ; Bagherzadeh, R ; Malekshahi Byranvand, M ; Naseri, N ; Dabirian, A ; Sharif University of Technology
John Wiley and Sons Ltd
Iron(III) oxide (hematite, Fe2O3) nanofibers, as visible light-induced photoanode for water oxidation reaction of a water splitting process, were fabricated through electrospinning method followed by calcination treatment. The prepared samples were characterized with scanning electron microscopy, and three-electrode galvanostat/potentiostat for evaluating their photoelectrochemical (PEC) properties. The diameter of the as-spun fibers is about 300nm, and calcinated fibers have diameter less than 110nm with mesoporous structure. Optimized multilayered electrospun α-Fe2O3 nanostructure mats showed photocurrent density of 0.53mA/cm2 under dark and visible illumination conditions at voltage 1.23V...
Graphitic carbon nitride (g-C3N4)-based photocatalysts for solar hydrogen generation: Recent advances and future development directions, Article Journal of Materials Chemistry A ; Volume 5, Issue 45 , 2017 , Pages 23406-23433 ; 20507488 (ISSN) ; Samadi, M ; Pourjavadi, A ; Moshfegh, A. Z ; Ramakrishna, S ; Sharif University of Technology
Royal Society of Chemistry 2017
Graphitic carbon nitride (g-C3N4) is a metal-free conjugated polymer constructed from two-dimensional sheets with a bandgap energy of 2.7 eV, which makes it an applicable and efficient visible-active photocatalyst for H2 production. In the present study, the basic concepts and principles of photocatalytic water splitting have been discussed, and a guide for the selection of appropriate photocatalysts, focusing on the g-C3N4 nanomaterials, has been proposed. Our approach is mainly concentrated on evaluating two factors, namely the solar-to-hydrogen (STH) conversion and apparent quantum yield (AQY) for different photocatalysts, to provide an in-depth analysis and a framework for solar H2...
Article Applied Surface Science ; Volume 550 , 2021 ; 01694332 (ISSN) ; Eftekharinia, B ; Tayebi, M ; Lee, B. K ; Naseri, N ; Sharif University of Technology
Elsevier B.V 2021
Hematite is recognized as a promising photoanode for photoelectrochemical water oxidation to produce solar hydrogen due to its favorable properties. However, the high charge carrier recombination rate due to low electrical conductivity and sluggish oxygen reduction kinetics of pure hematite hinder its photocatalytic activity. This work proposed a new hematite-based heterostructure of Ti-Fe2O3/Fe2TiO5/FeOOH, synthesized through a hydrothermal method. The photoanode morphology was branched nanorods that expanded their surface area and improved charge transfer at the photoanode/electrolyte interface. In a novel and complement modification approach, a thin pseudobrookite interlayer was applied...
Synthesis, Characterization and Photoelectrochemical Application of ZnO Nanorods Sensitized by Graphene, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza ; Naseri, Naeimeh
According to the growth in the world population and the decrease in fossil fuels resources and also according to the pollution caused by these unrenewable resources, using hydrogen as an alternative energy resource seems to be unavoidable. In the past decades, semi-conductor metal oxides were being used widely in the energy domain of study, due to their appropriate band gap in the ultra-violet and visible spectra. Among these metal oxides, ZnO has been under special attention because of its electron mobility and its reasonable production cost and also its friendliness to environment. But the high band gap of ZnO (3.2 eV) has impeded its use in visible light spectrum. In this project,...
Synthesis and Characterization of ZnO Nanostructure, Modified by Graphene and CdS for PEC Application, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza
In this project, the photoelectrochemical properties of ZnO nanostructures modified by CdS and Graphene was studied. Firs, titanium foil was cut into rectangular shape with 1cm width and 3 cm length, cleaned by rinsing in acetone and ethanol and annealed at 4000C for an hour. As a result, a thin layer of titanium oxide was formed on Ti sheet. Then a layer of grapheme oxide was deposited on substrate using Electrophoretic deposition (EPD). After that, ZnO nanostructure was deposited on the TiO2 substrate using Electropulsation (EP) with 20 consecutive pulse followed by 3 minutes Electrodeposition (ED). Using SEM analysis, the morphology of ZnO was determined to be nanopetals in which the...
An Investigation on Physical and Photochemical Properties of Sol-Gel Derived MWCNT-WO3 Nanocomposite thin Films, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza
WO3 have good electrochromic, gas sensor, photocatalyst, phoelectrochemical (PEC) properties. due its properties, tungsten oxide have many application in technology and industry. In this thesis, pure WO3 thin film and MWCNT-WO3 nanocomposite thin films with different weight percent of MWCNT/WO3 utilize for energy domain, particular hydrogen production with phoelectrochemical reactions spiliting water. For this purpose, initially WO3 thin films were deposited on glass and ITO substrates using sol-gel dip-coating method. Optical and surface properties of the films dried at 100ºC and annealed at 400 ºC had been investigated. UV-Visible spectrophotometer, atomic force microscopy (AFM), X-ray...
Fabrication of CuFe2O4/α-Fe2O3 composite thin films on FTO coated glass and 3-D nanospike structures for efficient photoelectrochemical water splitting, Article ACS Applied Materials and Interfaces ; Volume 8, Issue 51 , 2016 , Pages 35315-35322 ; 19448244 (ISSN) ; Hussain, S ; Waleed, A ; Tavakoli, M. M ; Wang, Z ; Yang, S ; Fan, Z ; Nadeem, M. A ; Sharif University of Technology
American chemical society 2016
Recently, photoelectrochemical conversion (PEC) of water into fuel is attracting great attention of researchers due to its outstanding benefits. Herein, a systematic study on PEC of water using CuFe2O4/ α-Fe2O3 composite thin films is presented. CuFe2O4/ α-Fe2O3 composite thin films were deposited on two different substrates; (1) planner FTO glass and (2) 3-dimensional nanospike (NSP). The films on both substrates were characterized and tested as anode material for photoelectrochemical water splitting reaction. During PEC studies, it was observed that the ratio between two components of composite is crucial and highest PEC activity results were achieved by 1:1 component ratio (CF-1) of...
Novel visible light photocatalytic and photoelectrochemical (PEC) activity of carbon-doped zinc oxide/reduced graphene oxide: supercritical methanol synthesis with enhanced photocorrosion suppression, Article Journal of Alloys and Compounds ; Volume 723 , 2017 , Pages 1001-1010 ; 09258388 (ISSN) ; Soltani, T ; Lee, B. K ; Outokesh, M ; Tayebi, M ; Sharif University of Technology
Carbon-doped zinc oxide/reduced graphene oxide (C-ZnO/rGO) was prepared by a facile one-pot supercritical methanol method. The synthesized C-ZnO/rGO nanocomposite with flower-like ZnO micro-rods (MRs) synergistically inherited all the advantages of carbon doping and rGO heterojunction and exhibited high photocatalytic activity for the photodegradation of methyl orange (MO) under visible light. The x-ray diffraction (XRD) results indicated that in presence of GO, a new carbon-doped phase was formed at the high temperature and pressure of supercritical methanol. The x-ray photoelectron spectroscopy (XPS) at low binding energies demonstrated that the valence band of C-ZnO-rGO is up-shifted by...
One-pot microwave synthesis of hierarchical C-doped CuO dandelions/g-C3N4 nanocomposite with enhanced photostability for photoelectrochemical water splitting, Article Applied Surface Science ; Volume 530 , 2020 ; Siavash Moakhar, R ; Soleimani, F ; Sadrnezhaad, S. K ; Masudy Panah, S ; Katal, R ; Seza, A ; Ghane, N ; Ramakrishna, S ; Sharif University of Technology
Elsevier B.V 2020
Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g-C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one-pot method is utilized to directly deposit the nanocomposite onto fluorine-doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g-C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically...
Article 237th ECS Meeting with the 18th International Meeting on Chemical Sensors, IMCS 2020, 10 May 2020 through 14 May 2020 ; Volume 97, Issue 7 , 2020 , Pages 845-856 ; Siavash Moakhar, R ; Soleimani, F ; Goudarzi, A ; Sadrnezhaad, S. K ; Sharif University of Technology
Institute of Physics Publishing 2020
In-situ deposition of cupric oxide (CuO) thin films on fluorine-doped tin oxide is performed through a rapid microwave-assisted method. The duration of microwave (MW) irradiation is optimized in order to prepare efficient and stable photocathodes for photoelectrochemical (PEC) water splitting. We obtain CuO with a unique morphology consisted of intermingled nanosheets. We evaluate PEC performance of the photocathodes through Linear Sweep Voltammetry (LSV) and current stability analyses. The highest achieved photocurrent density is -1.15 mA.cm-2 at 0 V vs. RHE for the sample MW-irradiated for 60 min. This value is comparable or superior to several other CuO-based photocathodes prepared by...
Carbon quantum dots modified anatase/rutile TiO2 photoanode with dramatically enhanced photoelectrochemical performance, Article Applied Catalysis B: Environmental ; Volume 269 , 2020 ; Chen, S ; Li, L ; Wang, J ; Zhang, Y ; Li, J ; Bai, J ; Xia, L ; Xu, Q ; Rahim, M ; Zhou, B ; Sharif University of Technology
Elsevier B.V 2020
TiO2 is a promising photoanode material for photoelectrochemical (PEC) water splitting, but its severe bulk recombination of photogenerated carriers, sluggish oxygen evolution reaction (OER) kinetics and poor visible light response are the main bottleneck problems. Here, the carbon quantum dots (CQDs) modified anatase/rutile TiO2 photoanode (CQDs/A/R-TiO2) was designed by growth of anatase TiO2 nanothorns on rutile TiO2 nanorods and further surface modification of CQDs. The results revealed that the A/R-TiO2 heterojunction significantly suppressed the bulk recombination of photogenerated carriers. With further incorporation of CQDs into A/R-TiO2, dramatical improvement of OER kinetics and...
Article Advanced Materials ; Volume 33, Issue 33 , 2021 ; 09359648 (ISSN) ; Hosseini Hosseinabad, S. M ; Masudy Panah, S ; Seza, A ; Jalali, M ; Fallah Arani, H ; Dabir, F ; Gholipour, S ; Abdi, Y ; Bagheri Hariri, M ; Riahi Noori, N ; Lim, Y. F ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
John Wiley and Sons Inc 2021
The cost-effective, robust, and efficient electrocatalysts for photoelectrochemical (PEC) water-splitting has been extensively studied over the past decade to address a solution for the energy crisis. The interesting physicochemical properties of CuO have introduced this promising photocathodic material among the few photocatalysts with a narrow bandgap. This photocatalyst has a high activity for the PEC hydrogen evolution reaction (HER) under simulated sunlight irradiation. Here, the recent advancements of CuO-based photoelectrodes, including undoped CuO, doped CuO, and CuO composites, in the PEC water-splitting field, are comprehensively studied. Moreover, the synthesis methods,...