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Improving the visible light photoelectrochemical activity of synthesized TiO2 nanotube arrays in an organic electrolyte containing sodium carbonate with doping by copper: Via single-step anodization
, Article New Journal of Chemistry ; Volume 41, Issue 19 , 2017 , Pages 10723-10730 ; 11440546 (ISSN) ; Yoozbashizadeh, H ; Sharif University of Technology
Royal Society of Chemistry
2017
Abstract
The main aim of this research is to improve the photocatalytic activity of TiO2 nanotubes by co-doping with copper and sodium for application in the water splitting process as a photoanode. The doping was performed simultaneously to the anodizing process through a single-step treatment. The synthesized TiO2 nanotube array (TNA) was characterized by applying FESEM (Field Emission Scanning Electron Microscopy), XRD (X-ray Diffraction), DRS (Diffraction Reflection Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy) analyses. The results of XPS analysis proved the presence of copper with valence (2+) and carbon and sodium with valence (1+). Moreover, DRS tests showed a reduction in the band...
Size and geometry of multielectrode arrays determine the efficiency of electrical interaction with neurons through double-layer capacitance
, Article IEEE Sensors Journal ; Volume 19, Issue 8 , 2019 , Pages 2829-2836 ; 1530437X (ISSN) ; Mohammadpour, R ; Vossoughi, M ; Sasanpour, P ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Multielectrode array (MEA) structures are the vital parts in the interface between neural structures and external electronic circuits, both in excitation and detection. As a transducer, the performance of electrodes has direct effect on the quality of the recorded neural signal, as well as induced charge density during the stimulation in neural prosthesis. The size and geometry of the electrode structure have distinct effect on the performance of electrodes accordingly. In this paper, the effect of size and geometry of the electrodes has been investigated in their performance and the impedimetric features of the fabricated electrodes with different structures have been studied. Based on the...
Facile synthesis of cotton flower like Ni–Co/Ni–Co–O–P as bifunctional active material for alkaline overall water splitting and acetaminophen sensing
, Article International Journal of Hydrogen Energy ; Volume 47, Issue 76 , 2022 , Pages 32516-32530 ; 03603199 (ISSN) ; Esfandiar, A ; Iraji zad, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The development of electrode materials with simple preparation, favorable price, excellent electrocatalytic activity, and stability are some of the most important issues in the field of electrochemistry. Herein, we prepared Ni–Co/Ni–Co–O–P cotton flower like on a copper sheet (CS) by a convenient, efficient, and scalable electrodeposition method. The Ni–Co/Ni–Co–O–P was employed as effective binder free electrode material in two different applications such as electrocatalytic water splitting and acetaminophen (APAP) sensor. Remarkably, the Ni–Co/Ni–Co–O–P@CS exhibits low overpotentials of 310 and 90 mV at 10 mA cm−2 for oxygen and hydrogen evolution reactions in alkaline media, respectively....
An ultrathin amorphous defective co-doped hematite passivation layer derived via an in situ electrochemical method for durable photoelectrochemical water oxidation
, Article Journal of Materials Chemistry A ; Volume 10, Issue 31 , 2022 , Pages 16655-16665 ; 20507488 (ISSN) ; Qorbani, M ; Sabbah, A ; Quadir, S ; Huang, C. Y ; Chen, K. H ; Chen, L. C ; Naseri, N ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
Although hematite (i.e., α-Fe2O3) has been widely investigated in photoelectrochemical water oxidation studies due to its high theoretical photocurrent density, it still suffers from serious surface charge recombination and low photoelectrochemical stability. Here we report an in situ electrochemical method to form a uniform and ultrathin (i.e., 3-5 nm) passivation layer all over the pores of an optimized ∼3.2% Ti-doped α-Fe2O3 photoanode. We unveil the amorphous and defective nature of the in situ derived layer assigned to a high concentration of oxygen vacancies and intercalated potassium atoms there, i.e., the formation of Ti/K co-doped defective α-Fe2O3−x. Owing to the efficient...
Ionic liquid/graphene oxide as a nanocomposite for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase
, Article Journal of Solid State Electrochemistry ; Volume 17, Issue 1 , January , 2013 , Pages 183-189 ; 14328488 (ISSN) ; Ghasemi, S ; Ghourchian, H ; Gholami, M. R ; Sharif University of Technology
2013
Abstract
By combination of 1-ethyl-3-methyl immidazolium ethyl sulfate as a typical room temperature ionic liquid (IL) and graphene oxide (GO) nanosheets, a nanocomposite was introduced for improving the direct electrochemistry and electrocatalytic activity of glucose oxidase (GOx). The enzyme on the IL-GO-modified glassy carbon electrode exhibited a quasireversible cyclic voltammogram corresponding to the flavine adenine dinucleotide/FADH2 redox prosthetic group of GOx. At the scan rate of 100 mV s-1, the enzyme showed a peak-to-peak potential separation of 82 mV and the formal potential of -463 mV (vs Ag/AgCl in 0.1 M phosphate buffer solution, pH 7.0). The kinetic parameters of the charge transfer...
Horseradish peroxidase immobilization on amine functionalized carbon nanotubes: Direct electrochemistry and bioelectrocatalysis
, Article Progress in Reaction Kinetics and Mechanism ; Volume 37, Issue 2 , May , 2012 , Pages 161-172 ; 14686783 (ISSN) ; Ghourchian, H ; Gholami, M. R ; Rafiee Pour, H. A ; Sharif University of Technology
2012
Abstract
Horseradish peroxidase (HRP) was successfully immobilized on amine functionalized TiO 2-coated multiwalled carbon nanotubes (NH 2-TiO 2-CNTs) by a convenient and efficient method. Electrochemical impedance spectroscopy, cyclic voltammetry and amperometry were applied to characterize the HRP/NH 2-TiO 2-CNT nano-composite. These techniques showed that the NH 2-TiO 2-CNTs greatly enhance the electron transfer between HRP and the modified electrode. Owing to the redox reaction of the electroactive centre of HRP, the HRP/NH 2-TiO 2-CNTs modified electrode exhibited a pair of quasi-reversible peaks with a peak-to-peak separation (ΔE p) of 70.6mV and a formal potential (E 0′) of -367.65mV (versus...
Amine functionalized TiO2 coated on carbon nanotube as a nanomaterial for direct electrochemistry of glucose oxidase and glucose biosensing
, Article Journal of Molecular Catalysis B: Enzymatic ; Volume 68, Issue 2 , 2011 , Pages 206-210 ; 13811177 (ISSN) ; Rafiee Pour, H. A ; Ghourchian, H ; Gholami, M. R ; Sharif University of Technology
Abstract
A nano-composite material consisting of amine functionalized TiO 2-coated carbon nanotubes was prepared and used for glucose oxidase (GOx) absorption. The GOx bearing nanomaterial was fixed on a glassy carbon electrode to construct a novel biosensor for glucose determination. The direct electrochemistry of immobilized GOx and its electron transfer parameters at the modified glassy carbon electrode were reported. The apparent heterogeneous electron transfer rate constant (ks) of GOx was estimated to be 3.5 s-1, which is higher than those reported previously. Amperometric detection of glucose resulted in a rapid (3 s) and stable response in the linear concentration range from 1.8 to 266 μM....
A highly thermal-resistant electrospun-based polyetherimide nanofibers coating for solid-phase microextraction Microextraction Techniques
, Article Analytical and Bioanalytical Chemistry ; Vol. 406, issue. 8 , March , 2014 , p. 2141-2149 ; Akbarinejad, A ; Aghakhani, A ; Sharif University of Technology
Abstract
A high-temperature-resisant solid-phase microextraction (SPME) fiber was prepared based on polyetherimide (PEI) by the electrospinning method. The PEI polymeric solution was converted to nanofibers using high voltages and directly coated on a stainless steel SPME needle. The scanning electron microscopy images of PEI coating showed fibers with diameter range of 500-650 nm with a homogeneous and smooth surface morphology. The SPME nanofibers coating was optimized for PEI percentage, electrospinning voltage, and time. The extraction efficiency of the coating was investigated for headspace SPME of some environmentally important polycyclic aromatic hydrocarbons from aqueous samples followed by...
Controlled engineering of WS2 nanosheets-CdS nanoparticle heterojunction with enhanced photoelectrochemical activity
,
Article
Solar Energy Materials and Solar Cells
;
Volume 141
,
2015
,
Pages 260-269
;
09270248 (ISSN)
; Zhao, M
; Moradlou, O
; Samadi, M
; Sarikhani, N
; Wang, Q
; Zhang, H. L
; Moshfegh, A. Z
;
Sharif University of Technology
Elsevier
2015
Abstract
Abstract We report the well-controlled preparation of WS2 nanosheets-CdS nanoparticle heterojunction for photoelectrochemical (PEC) water splitting application. The WS2 nanosheets with an average thickness of ~5 nm and lateral dimensions of ~200 nm were synthesized via liquid phase exfoliation of bulk WS2 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/WS2 /ITO and WS2 /CdS/ITO systems were fabricated. The loading of WS2 nanosheets was...
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
Abstract
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...
Constructing BiVO4/Graphene/TiO2 nanocomposite photoanode for photoelectrochemical conversion applications
, Article Journal of Electroanalytical Chemistry ; Volume 763 , 2016 , Pages 1-9 ; 15726657 (ISSN) ; Faraji, M ; Moshfegh, A. Z ; Sharif University of Technology
Elsevier B.V
2016
Abstract
BiVO4/Graphene/TiO2 as a novel nanocomposite photoanode was designed, synthesized and characterized for photoelectrochemical application. BiVO4/Graphene nanocomposite was initially synthesized by photocatalytic process and then, BiVO4/Graphene/TiO2 nanocomposite thin film was prepared by deposition of the BiVO4/Graphene solution onto the surface of sol-gel derived TiO2 thin film. Morphology, crystal structure, surface chemical composition and optical properties of the synthesized BiVO4/Graphene/TiO2 nanocomposite thin film were characterized and compared with the BiVO4/Graphene and pure TiO2 samples. Observations of scanning electron microscopy (SEM) images revealed that the surface of the...
Enhanced photoelectrochemical processes by interface engineering, using Cu2O nanorods
, Article Materials Letters ; Volume 163 , 2016 , Pages 81-84 ; 0167577X (ISSN) ; Mohammad Pour, R ; Iraji Zad, A ; Sharif University of TEchnology
Elsevier
Abstract
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...
Enhancement in solar driven water splitting by Au–Pd nanoparticle decoration of electrochemically grown ZnO nanorods
, Article Journal of Applied Electrochemistry ; Volume 46, Issue 8 , 2016 , Pages 819-827 ; 0021891X (ISSN) ; Kushwaha, A ; Jalali, M ; Goh, G. K. L ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
Springer Netherlands
Abstract
Oriented ZnO nanorods were grown directly on fluorine doped tin oxide substrates by a single bath electrodeposition process. A pulse potential at the beginning of growth improved the density and orientation of the nanorods. Pulse potential grown ZnO nanorod films showed better harvesting of visible light and enhanced the light driven water splitting performance in comparison to nanorods grown without any pulse potential. To further improve the water splitting activity, the nanorods were decorated with gold–palladium nanoparticles by sputtering. This caused visible light absorption to increase due to a plasmonic effect and the photoelectrochemical water splitting performance to further...
Spray pyrolysis deposition of ZnFe2O4/Fe2O3 composite thin films on hierarchical 3-D nanospikes for efficient photoelectrochemical oxidation of water
, Article Journal of Physical Chemistry C ; Volume 121, Issue 34 , 2017 , Pages 18360-18368 ; 19327447 (ISSN) ; Hussain, S ; Waleed, A ; Tavakoli, M. M ; Yang, S ; Khawar Rauf, M ; Fan, Z ; Arif Nadeem, M ; Sharif University of Technology
Abstract
In this work, we study the role of nanotextured ZnFe2O4/Fe2O3composite thin films fabricated by ultrasonic spray pyrolysis (USP) on the photoelectrochemical water oxidation reactions. The ZnFe2O4/Fe2O3 composites with different molar ratios are deposited on three-dimensional nanospikes (NSP) substrate, and the results are compared with those for planar devices. It is observed that optical absorption and charge separation due to larger surface area is significantly enhanced in nanotextured photoactive ZnFe2O4/Fe2O3 films. After characterization of ZnFe2O4/Fe2O3 composite films with different molar ratios (ZF1, ZF2, and ZF3), we find that the nanotextured ZF1 composite with a molar ratio of...
Synthesis, properties and biomedical applications of carbon-based quantum dots: an updated review
, Article Biomedicine and Pharmacotherapy ; Volume 87 , 2017 , Pages 209-222 ; 07533322 (ISSN) ; Negahdari, B ; Eatemadi, A ; Sharif University of Technology
Elsevier Masson SAS
2017
Abstract
Carbon-based quantum dots (CQDs) are a newly developed class of carbon nano-materials that have attracted much interest and attention as promising competitors to already available semiconductor quantum dots owing to their un-comparable and unique properties. In addition, controllability of CQDs unique physiochemical properties is as a result of their surface passivation and functionalization. This is an update article (between 2013 and 2016) on the recent progress, characteristics and synthesis methods of CQDs and different advantages in varieties of applications. © 2017 Elsevier Masson SAS
Sunlight-driven photoelectrochemical sensor for direct determination of hexavalent chromium based on Au decorated rutile TiO2 nanorods
, Article Applied Catalysis B: Environmental ; Volume 201 , 2017 , Pages 411-418 ; 09263373 (ISSN) ; Goh, G. K. L ; Dolati, A ; Ghorbani, M ; Sharif University of Technology
Elsevier B.V
2017
Abstract
A highly sensitive and selective sunlight-driven photoelectrochemical sensor for the direct detection and reduction of chromium(VI) was developed based on single crystal rutile titanium dioxide nanorods decorated with gold nanoparticles. Under sun simulator illumination via the amperometric technique, these Au decorated TiO2 photoelectrodes exhibited the highest sensitivity (13.94 μA μM−1) ever reported among Au-based electrodes for Cr(VI) detection, with a very low detection limit (S/N = 3) of 0.006 μM and wide linear concentration range from 0.01 μM to 50 μM. Measurements in real water samples such as laboratory and river water also showed excellent anti-interference and recovery...
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
Abstract
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...
Photoelectrochemical activity of graphene quantum dots/hierarchical porous TiO2 photoanode
, Article Journal of Alloys and Compounds ; Volume 721 , 2017 , Pages 36-44 ; 09258388 (ISSN) ; Safa, S ; Ebrahimi, M ; Yousefzadeh, S ; Moshfegh, A. Z ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
In this study, initially graphene quantum dots (GQDs) were synthesized by an electrochemical technique and hierarchical porous TiO2 were made by a sol – gel method. Subsequently, GQDs/hierarchical porous TiO2 nanocomposites were prepared by two different methods for the purpose of comparison: spin coating (SC) and electrophoretic (EP) deposition. The GQDs/hierarchical porous TiO2 nanocomposites were characterized by various analytical methods including field emission scanning electron microscopy, atomic force microscopy, transmission electron microscopy, high resolution transmission electron microscopy, Fourier transform infra-red spectroscopy, photoluminescence spectroscopy and...
Nanotextured spikes of α-Fe2O3/NiFe2O4 composite for efficient photoelectrochemical oxidation of water
, Article Langmuir ; Volume 34, Issue 12 , 2018 , Pages 3555-3564 ; 07437463 (ISSN) ; Tavakoli, M. M ; Waleed, A ; Virk, U. S ; Yang, S ; Waseem, A ; Fan, Z ; Nadeem, M. A ; Sharif University of Technology
American Chemical Society
2018
Abstract
We demonstrate for the first time the application of p-NiFe2O4/n-Fe2O3 composite thin films as anode materials for light-assisted electrolysis of water. The p-NiFe2O4/n-Fe2O3 composite thin films were deposited on planar fluorinated tin oxide (FTO)-coated glass as well as on 3D array of nanospike (NSP) substrates. The effect of substrate (planar FTO and 3D-NSP) and percentage change of each component (i.e., NiFe2O4 and Fe2O3) of composite was studied on photoelectrochemical (PEC) water oxidation reaction. This work also includes the performance comparison of p-NiFe2O4/n-Fe2O3 composite (planar and NSP) devices with pure hematite for PEC water oxidation. Overall, the nanostructured...
Electrochemical impedance studies of methanol oxidation on GC/Ni and GC/NiCu electrode
, Article International Journal of Hydrogen Energy ; Volume 34, Issue 2 , 2009 , Pages 859-869 ; 03603199 (ISSN) ; Jafarian, M ; Forouzandeh, F ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
2009
Abstract
The electro-oxidation of methanol on nickel and nickel-copper alloy modified glassy carbon electrodes (GC/Ni and GC/NiCu) in a 1 M NaOH solution at different concentrations of methanol was studied by the method of ac-impedance spectroscopy. Two semicircles in the first quadrant of a Nyquist diagram were observed for electro-oxidation of methanol on GC/Ni corresponding to charge transfer resistance and adsorption of intermediates. Electro-oxidation of methanol on GC/NiCu shows negative resistance in impedance plots as signified by semi-circles terminating in the second quadrant. The impedance behavior shows different patterns at different applied anodic potential. The influence of the...