77 research outputs found
Ni3S4/NiS/rGO as a promising electrocatalyst for methanol and ethanol electro-oxidation
No full textWe present a one-step hydrothermal synthesis of hybrids consisting of nickel sulfides in the form of Ni3S4-NiS (NN) and Ni3S4–NiS-rGO (NNR), i.e. with the addition of reduced graphene oxide (rGO), for application as catalysts. After accurate physical characterization and confirmation of
the successful synthesis, we evaluate the ability of these catalysts in the processes of methanol and ethanol oxidation. The precise electrochemical analyses show relatively good potential and excellent cyclic stability in methanol oxidation reaction and ethanol oxidation reaction processes.
The comparison of the two catalysts shows the superiority of NNR over NN confirming that rGO introduces a higher specific surface area and a higher electrical conductivity in the NNR structure.
In the process of MOR, NNR has an oxidation peak at a current density of 55 mA cm–2 and a peak potential of 0.54 V. In EOR, this peak is located at a current density of 11 mA cm–2 and at a peak potential of 0.59 V. NNR has 97% and 94% stability in MOR and EOR after 1000 consecutive cycles, respectively which are acceptable values
MnCo2O4/NiCo2O4/rGO as a Catalyst Based on Binary Transition Metal Oxide for the Methanol Oxidation Reaction
No full textThe demands for alternative energy have led researchers to find effective electrocatalysts in fuel cells and increase the efficiency of existing materials. This study presents new nanocatalysts based on two binary transition metal oxides (BTMOs) and their hybrid with reduced graphene oxide for methanol oxidation. Characterization of the introduced three-component composite, including cobalt manganese oxide (MnCo2O4), nickel cobalt oxide (NiCo2O4), and reduced graphene oxide (rGO) in the form of MnCo2O4/NiCo2O4/rGO (MNR), was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray (EDX) analyses. The alcohol oxidation capability of MnCo2O4/NiCo2O4 (MN) and MNR was evaluated in the methanol oxidation reaction (MOR) process. The crucial role of rGO in improving the electrocatalytic properties of catalysts stems from its large active surface area and high electrical conductivity. The alcohol oxidation tests of MN and MNR showed an adequate ability to oxidize methanol. The better performance of MNR was due to the synergistic effect of MnCo2O4/NiCo2O4 and rGO. MN and MNR nanocatalysts, with a maximum current density of 14.58 and 24.76 mA/cm2 and overvoltage of 0.6 and 0.58 V, as well as cyclic stability of 98.3% and 99.7% (at optimal methanol concentration/scan rate of 20 mV/S), respectively, can be promising and inexpensive options in the field of efficient nanocatalysts for use in methanol fuel cell anodes
CeO2-NiO-rGO as a nano-electrocatalyst for methanol electro-oxidation
No full textThis study provides the methanol oxidation capability of two nanocatalysts, CeO2-NiO (CN) and CeO2-NiO-rGO (CNR), synthesized by a cost-effective hydrothermal method. The synergistic effect of compositing CeO2-NiO with reduced graphene oxide was evaluated. These synergic effect makes a good electrochemical active surface area and suitable electrical conductivity for catalyst. In addition, rGO with good electrical conductivity revealed considerable improvement in the methanol oxidation reaction (MOR) performance of the catalyst. The cyclic stability measurements of CeO2-NiO-rGO showed a high retention ability of 96% in 500 consecutive CV cycles, while the stability of CeO2-NiO in the same number of cycles is about 93%. The complementary methanol oxidation process results indicated an oxidation current density up to 49.5 and 68.5 mA/cm2 for CN and CNR at a scan rate of 20 mV/s, respectively. The proposed catalyst can be considered as an attractive, stable, and inexpensive candidate in the field of methanol oxidation to use in methanol fuel cells
Correction To: A Heuristic Approach to Predict the Tensile Strength of a Non-Persistent Jointed Brazilian Disc under Diametral Loading (Bulletin of Engineering Geology and the Environment, (2022), 81, 9, (364), 10.1007/s10064-022-02869-8)
No full textOriginally, there is a mistake in the affiliation of the third author. Taghi sherizadeh has just one affiliation as follows: Department of Mining and Nuclear Engineering, Missouri, University of Science and Technology, Rolla, MO 65409, USA The original article has been corrected
Correction to: Evaluation of serum 25-Hydroxy vitamin D levels in children with autism Spectrum disorder
No full textThe original article [1] contained an error in author Mohammad Taghi Mansouri’s name
<i>Riga-Fede disease</i>: A histological study and case report
No full textAcute traumatic ulcerations and granulomas of the oral mucosa may result from physical damage via sharp foodstuffs, accidental biting, or talking. Most ulcerations heal within days. Others become chronic, reactive, and exophytic. A histopathologically unique type of chronic traumatic ulceration is the traumatic ulcerative granuloma with stromal eosinophilia (TUGSE). TUGSE exhibits a deep "pseudoinvasive" inflammatory reaction. This lesion may occur under the tongue in infants as a result of chronic mucosal trauma caused by mandibular anterior primary teeth during nursing and is termed Riga-Fede disease (RFD). The clinical presentation many resemble squamous cell carcinoma causing concern. RFD, although not uncommon, is not frequently reported. Thus, dental practitioners are unfamiliar with such lesions. We present a large Riga-Fede lesion in an infant along with the clinical management
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