Exploring highly active, stable, and inexpensive electrocatalysts for the oxygen reduction reaction (ORR) is pivotal in developing high-performance energy conversion devices. Moreover, the production of catalysts containing transition metals with the appropriate nitrogen doping level is a potential approach to increase ORR catalytic efficiency, especially under acidic conditions. In this study, a hierarchical graphitic porous carbon-containing Fe and N was obtained via pyrolysis of a bimetal MOF (Fe/ZIF-8) composited with pyrrole. Further experimental and theoretical results confirmed that the synergistic effects between Fe-based nanoparticles and N-doping in the networks are likely form one of the main reasons for better ORR performance. U
Novel Magnetic Flowable Electrode for Redox Flow Batteries: A Polysulfide/Iodide Case Study
Mohammad Rahimi, Asghar Molaei Dehkordi, Hussein Gharibi, Edward PL Roberts
Journal PapersIndustrial & Engineering Chemistry Research , Volume 60 , Issue 2, 2021 January 5, {Pages 824-841 }
Abstract
A novel approach named a magnetic flowable electrode (MFE) is proposed for the first time to enable enhancement of redox flow batteries (RFBs) performance. This approach enables the formation of a high active surface area electrode from magnetic nanomaterials, without the need to fabricate a self-supporting three-dimensional electrode structure. To form a simple MFE, magnetic modified carbon nanotubes are dispersed in the electrolyte, and permanent magnets are embedded behind the current feeder to apply a magnetic field across the flow cell channels. With circulating electrolyte, magnetic carbon nanotubes are aggregated on the graphite bipolar plate to form a well-structured nanoscale percolating network and chains serving as an electrode.
Metal organic framework derived iron-nitrogen doped porous carbon support decorated with cobalt and iron as efficient nanocatalyst toward oxygen reduction reaction
Maryam Maryam Jafari, Hussein Gharibi, Mohammad Javad Parnian
Journal PapersJournal of Power Sources , Volume 499 , 2021 May 5, {Pages 229956 }
Abstract
Two porous carbon supports as N-doped carbon (NC) and Fe/N-co-doped carbon (Fe-NC), are obtained from ZIF-8 (zeolitic imidazolate framework) and Fe@ZIF-8, respectively, through the pyrolysis process. They are then decorated with transition metals using a modified polyol method to precipitate Fe, Co, and Fe–Co nanoparticles. The as-prepared catalysts are characterized by different physicochemical, morphological, and electrochemical characterization methods. Field emission scanning electron microscopy images show well-defined preserved polyhedron morphology for all prepared catalysts. Transmission electron microscopy images confirm a uniform distribution of metal nanoparticles through the surface of the supports. X-ray photoelectron spectro
Single-layer phosphorene is a unique material with distinctive properties resulting in its high potential to be used as an anode in alkali metal ion batteries (AIBs). In this study, the improvement of the adsorption energy, the diffusion, and the storage capacity of alkali metals (Li, Na, and K) in a pristine and defective monolayer phosphorene was systematically studied using first-principles calculations. All possible defects on phosphorene were studied by electronic structure analysis. The pristine phosphorene strongly adsorbed Li, Na, and K with adsorption energies of −2.08 eV, −1.33 eV, and −2.16 eV, respectively. Interestingly, the presence of point defects significantly enhanced the binding of the alkali metals with adsorption
Effect of imidazolium-based ionic liquid as electrolyte additive on electrochemical performance of 18650 cylindrical Li-ion batteries at room and 60? C temperatures
Journal PapersJournal of the Iranian Chemical Society , Volume 16 , Issue 10, 2019 October 1, {Pages 2123-2134 }
Abstract
To optimize the electrochemical performance and greater safety of Li-ion batteries (LIBs) in order to meet the market demands, an imidazolium-based ionic liquid (IL), namely 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIm][PF6]) as a commercially available and most widely studied IL, was synthesized and applied as electrolyte additive in commercial 18650 LIBs. The different compositions of mixed electrolyte were prepared by adding 0–5?wt% of IL to the organic electrolyte. The electrochemical measurements were done using galvanostatic charge and discharge and electrochemical impedance spectroscopy, EIS, analyses to obtain the optimal percentage of additive resulting in highest cycleability and discharge capacity as t
Phosphorene and graphene flakes under the effect of external electric field as an anode material for high-performance lithium-ion batteries: A first-principles study
A new phenomenon, i.e. the improvement of the adsorption energy and the diffusion of Li ion in a phosphorene monolayer under the effect of perpendicular external electric field (EEF) was studied using M06-2X/6-31G(d,p) density functional theory (DFT) framework, and also outcomes were compared with the results obtained by using of graphene. Potential energy surface (PES) scanning and analysis of origin-dependency of charged molecular systems’ energy, were used to obtain intrinsic binding energy of the charged molecular compounds within the external electric field. Our calculations revealed that, increasing the strength of field from −0.02 to 0.032 a u, caused the adsorption energies of the Li ion in the phosphorene monolayer to be incr
Insights on the superior performance of nanostructured nitrogen-doped reduced graphene oxide in comparison with commercial Pt/C as cathode electrocatalyst layer of passive?…
Ali Farzaneh, Elaheh K Goharshadi, Hussein Gharibi, Naser Saghatoleslami, Hossein Ahmadzadeh
Methanol crossover is one of the major problems which reduces the performance of direct methanol fuel cells (DMFCs). Utilization of methanol tolerant cathode electrocatalysts with comparable activity, lower cost, and higher durability than those of current Pt-based electrocatalysts is an essential step towards commercialization of DMFCs. In this research, for the first time the performance of hydrothermally produced nitrogen-doped reduced graphene oxide (NRGO) with nitrogen content of 4.6 wt% was compared with that of commercial 20 wt% Pt/C as cathode electrocatalysts of passive DMFC. The polarization curves of cells with various methanol concentrations (1.5, 3.0, and 4.5 M) were recorded. The results suggested the cell with NRGO cath
Co-solvent Effect on Spontaneous Formation of Large Nanoscale Structures in Catanionic Mixtures in the Anionic-Rich Region
Farhad Golmohammadi, Masoud Amiri, Hussein Gharibi, Ali Yousefi, Meysam Safari
Journal PapersJournal of Solution Chemistry , 2019 January , {Pages 18-Jan }
Abstract
The aggregation behavior was investigated in mixtures of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB)(anionic-rich catanionic) solutions. The study was conducted in solutions of water–ethylene glycol (EG) by means of surface tension, conductometry, cyclic voltammetry, zeta potential measurements, transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The degree of counterion dissociation (α), critical micelle concentration, aggregation numbers, interfacial properties, interparticle interaction parameters, and morphology of aggregates were determined. Based on regular solution theory, the cosolvent effects between SDS and CTAB as surfactants were also analyzed for both mixed monolay
Effect of imidazolium-based ionic liquid as electrolyte additive on electrochemical performance of 18650 cylindrical Li-ion batteries at room and 60° C temperatures
S Javadian, P Salimi, H Gharibi, A Fathollahi, E Kowsari, J Kakemam
Insights on the superior performance of nanostructured nitrogen-doped reduced graphene oxide in comparison with commercial Pt/C as cathode electrocatalyst layer of passive …
A Farzaneh, EK Goharshadi, H Gharibi, N Saghatoleslami, ...
Preparation of bimetallic alloyed palladium-nickel electro-catalysts supported on carbon with superior catalytic performance towards oxygen reduction reaction
Fereshteh Dehghani Sanij, Hussein Gharibi
Journal PapersColloids and Surfaces A: Physicochemical and Engineering Aspects , Volume 538 , 2018 February 5, {Pages 429-442 }
Abstract
Bimetallic alloyed palladium-nickel electro-catalysts supported on carbon (Vulcan XC-72) with various Pd to Ni atomic ratios have been successfully synthesized by an impregnation technique for the oxygen reduction reaction (ORR). The electro-catalysts are structurally characterized by XRD, FESEM-EDX, ICP-OES, TEM, and XPS. The EDX and mapping images confirm that Pd and Ni elements have been uniformly dispersed in the Pd8Ni2/C. TEM images illustrate that the metallic nanoparticles have been considerably distributed on the substrate with low agglomeration. Cyclic voltammetry (CV), rotating disk electrode (RDE), and chronoamperometry (CA) are applied to specify the electrochemical properties of the Pd-Ni alloys. It is demonstrated that the Pd8
Turning an environmental problem into an opportunity: potential use of biochar derived from a harmful marine biomass named Cladophora glomerata as anode?…
Journal PapersEnvironmental Science and Pollution Research , Volume 24 , Issue 36, 2017 December 1, {Pages 27974-27984 }
Abstract
The electrochemical performance of lithium ion battery was enhanced by using biochar derived from Cladophora glomerata (C. glomerata) as widespread green macroalgae in most areas of the Iran’s Caspian sea coast. By the utilization of the structure of the biochar, micro-/macro-ordered porous carbon with olive-shaped structure was successfully achieved through pyrolysis at 500??C, which is the optimal temperature for biofuel production, and was activated with HCl. The biochar and HCl treatment biochar (HTB) were applied as anode electrode in lithium ion batteries. Then, electrochemical measurements were conducted on the electrodes via galvanostatic charge–discharge, cyclic voltammetry (CV), and electrochemical impedance spe
Journal PapersInternational Journal of Hydrogen Energy , Volume 42 , Issue 18, 2017 May 4, {Pages 13136-13149 }
Abstract
CoSn4 nano-particles were synthesized on Cu and Ni substrates through pulsed current electrodeposition and used as anode in lithium ion batteries. Nano particles with Flower-like morphology were obtained through applying an average current density of 85?mA/cm2 on Ni substrate while the particles formed using constant current electrodeposition are greater in size ca. 500?nm. Optimum discharge capacity of synthesized CoSn4 was obtained 848?mAh?g−1 which reduced to 500?mAh?g−1 at 120th cycle indicating an enhanced electrochemical performance compared to anode films synthesized through other pulsed current densities and also constant current electrodeposition. This high discharge capacity and cycleability is attributed to finer crystal grai
Journal PapersNew Journal of Chemistry , Volume 41 , Issue 21, 2017 January , {Pages 12442-12450 }
Abstract
In this paper, we report the synthesis of titanium dioxide nanoarrays (TNAs) via an anodization process using different counter electrodes, including Pt, Ni, Ti, Cu, Al, and graphite. The synthesized TNAs are studied as anode materials for lithium ion batteries. The crystallographic structure and surface morphology of the TNAs are studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). Electrochemical tests of the TNA-Li half-cells are carried out using cyclic voltammetry (CV), charge/discharge analysis, and electrochemical impedance spectroscopy (EIS). These results show that the TNA morphologies and crystallography strongly depend on the type of counter electrode. The synthesis of TNAs using Pt and A
Turning an environmental problem into an opportunity: potential use of biochar derived from a harmful marine biomass named Cladophora glomerata as anode …