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Article
Publication date: 3 July 2017

Behnam Seyyedi

The purpose of this paper is to introduce bio-inspired FeN4-S-C black nano-electrocatalyst for the oxygen reduction reaction (ORR) in an alkaline medium. The FeN4-S-C derived…

Abstract

Purpose

The purpose of this paper is to introduce bio-inspired FeN4-S-C black nano-electrocatalyst for the oxygen reduction reaction (ORR) in an alkaline medium. The FeN4-S-C derived without pyrolysis of precursors in high temperature is recognized as a new electrocatalyst for the ORR in an alkaline electrolyte. For the proper design of bio-inspired nano-electrocatalyst for the ORR performance, chlorinated iron (II) phthalocyanine nanoparticles were used as templates for achieving the active sites in aqueous KOH by rotating disk electrode methods. The most active FeN4-S-C catalyst exhibited a remarkable ORR activity in the alkaline medium. The objectives of this paper are to investigate the possibility of nanoscale particles size (˜5nm) of electrocatalyst, to achieve four-electron transfer mechanism and to exhibit much superior catalytic stability in measurements. This paper will shed light on bio-inspired FeN4-S-C materials for the ORR catalysis in alkaline fuel cells.

Design/methodology/approach

The paper presents a new bio-inspired nano-electrocatalyst for the ORR, which has activity nearby platinum/carbon electrocatalyst. Chlorinated iron phthalocyanine nanoparticles have been used as FeN4 template, which is the key point for the ORR. Bio-inspired nano-electrocatalyst has been fabricated using chlorinated iron phthalocyanine, sodium sulphide and carbon black.

Findings

The particles’ size was 5 nm and electron transfer number was 4.

Research limitations/implications

The catalyst that is used in this method should be weighed carefully. In addition, the solvent should be a saturated solution of NaCl in water.

Practical implications

The method provides a simple and practical solution to improving the synthesis of iron-based catalyst for ORR.

Originality/value

The method for the synthesis of bio-inspired electrocatalyst was novel and can find numerous applications in industries, especially as ORR non-precious metal catalyst.

Details

Pigment & Resin Technology, vol. 46 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 26 January 2021

Ibrahim A. Amar and Mohammed M. Ahwidi

This paper aims to investigate the electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite (CFMo-CGDC) for the direct synthesis of ammonia from H2O and N2

Abstract

Purpose

This paper aims to investigate the electrocatalytic activity of CoFe1.9Mo0.1O4-Ce0.8Gd0.18Ca0.02O2-δ composite (CFMo-CGDC) for the direct synthesis of ammonia from H2O and N2 under atmospheric pressure.

Designs

CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using X-ray diffraction (XRD), Brunauer–Emmet–Teller (BET) specific surface area measurement and scanning electron microscope (SEM). Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied.

Findings

CoFe1.9Mo0.1O4 nanoparticles (CFMo NPs) were synthesized via a sol-gel method. CFMo NPs were characterized using XRD, Brunauer–Emmet–Teller (BET) specific surface area measurement and SEM. Double-chamber reactor was used to synthesize ammonia using H2O and N2 as precursors. The factors affecting the ammonia formation rate (applied voltage and temperature) were studied.

Originality/value

The usage of CFMo-CGDC composite as an electrocatalyst for the synthesis of ammonia directly from H2O and N2.

Details

World Journal of Engineering, vol. 18 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 10 December 2019

Zeinab Abdel Hamid, H.B. Hassan and Mohamed Sultan

The improvement of the hydrogen evolution reaction (HER) performance requires more efficient and inexpensive electrocatalysts. The purpose of this study is to prepare Ni-W and…

Abstract

Purpose

The improvement of the hydrogen evolution reaction (HER) performance requires more efficient and inexpensive electrocatalysts. The purpose of this study is to prepare Ni-W and Ni-W-P thin films using the electrodeposition technique using a pulse current and investigate their behaviors toward HER in an acidic solution.

Design/methodology/approach

The aim is to prepare Ni-W and Ni-W-P films by the electrodeposition technique using a pulse current and estimate their performance for the HER. The surface morphologies and chemical compositions of the deposited films were assessed using scanning electron microscopy, energy-dispersive X-ray analysis and X-ray diffraction. Linear sweep voltammetry, chronoamperometry, Tafel plots and electrochemical impedance spectroscopy were used to evaluate the prepared electrodes toward the hydrogen evolution process.

Findings

The main conclusion is that the surface morphology of Ni–W deposited film is a crystalline structure, while that of Ni-W-P deposit is an amorphous structure. HER activity on Ni-W electrodes increases with decreasing the Wt.% of W to 7.83 Wt.% in the prepared electrodes. In addition, the presence of P enhances HER activity, which increases with increasing the Wt.% of P in the prepared Ni-W-P electrodes. Both Ni-W (7.83 Wt.% W) and Ni-W-P (20.34 Wt.% P), which have been prepared at 8 A dm−2 display the best performance toward HER compared to the other prepared electrodes. They exhibit high catalytic activities toward HER, which is evidenced by high hydrogen evolution current density values of 9.52 and 33.98 mA cm−2, low onset potentials of −0.73 and −0.63 V, low Tafel slopes of −125 mV/dec, high exchange current densities of 0.058 and 0.20 mA cm−2, low charge transfer resistances (Rct) of 226.28 and 75.8 ohm·cm2 for Ni-W (7.83  Wt.% W) and Ni-W-P (20.34  Wt.% P), respectively; moreover, they exhibited considerable stabilities too.

Originality/value

The results presented in this work are an insight into understanding the performance of the prepared Cu electrodes coated by Ni-W and Ni-W-P films toward HER. In this work, a consistent assessment of the results achieved on laboratory scale has been conducted.

Article
Publication date: 5 January 2015

H.Y. Zhang, H.J. Niu, Y.M. Wang, C. Wang, X.D. Bai,, S. Wang and Wen Wang

The purpose of this paper was to provide a simple method for the preparation of carbon nanotubes (CNTs) by pyrolysing sunflower seed hulls and sago and to evaluate the application…

Abstract

Purpose

The purpose of this paper was to provide a simple method for the preparation of carbon nanotubes (CNTs) by pyrolysing sunflower seed hulls and sago and to evaluate the application of such CNTs in supercapacitors.

Design/methodology/approach

The CNTs were obtained by pyrolysing sunflower seed hulls and sago at 800°C. The prepared CNTs were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammograms, galvanostatic charge and discharge and electrochemical impedance spectra methods.

Findings

The CNTs had large surface areas as determined by the methylene blue method and the Brunauer – Emmett – Teller method. And the CNTs that were prepared by pyrolysing the natural sunflower seed hulls (denoted as CNTs-1) and sago (denoted as CNTs-2) had capacitances of 86.9 F/g and 26.7 F/g, respectively.

Research limitations/implications

The capacitances of CNTs can be further improved.

Practical implications

The exceptional electronic and mechanical properties of CNTs prepared lend the CNTs to diverse applications including electrocatalysts, hydrogen storage, photovoltaic devices actuators, energy storage, field-emitting flat panel displays and composites.

Originality/value

Currently, CNTs have not yet been used in the industry at a mass production scale due to high costs associated. The outcomes of the study reported in this article could provide a convenient method in aid of industrialisation of the production of CNTs.

Details

Pigment & Resin Technology, vol. 44 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 6 March 2017

Behnam Seyyedi

The paper introduces a microwave and electrochemical-assisted method for synthesis of chlorine-derived iron phthalocyanine pigment and oxygen reduction reaction catalyst…

Abstract

Purpose

The paper introduces a microwave and electrochemical-assisted method for synthesis of chlorine-derived iron phthalocyanine pigment and oxygen reduction reaction catalyst nanoparticles. The aims of this study are to investigate the possibility of nano-scale particle size (<35 nm), high-efficiency product reaction, remove acidic wastewater, time optimization and maximize number of chlorine on aromatic rings.

Design/methodology/approach

The paper presents a combined synthesis technique, which does not have the problems of the conventional methods. Chlorinated iron phthalocyanine nanoparticles have been fabricated using phthalic anhydride, urea (high purity), electrochemical-generated iron (II) cations and microwave irradiation as promoter. The approach yields a product of high quality, uniform particle size distribution and high efficiency and that was environment-friendly.

Findings

The particle size and time needed for the production of chlorinated iron phthalocyanine were about 35 nm and 7 min, respectively.

Research limitations/implications

The catalyst, that is used in this method, should be weighed carefully. In addition, the solvent should be a saturated solution of NaCl in water.

Practical implications

The method provides a simple and practical solution to improving the synthesis of an iron-based catalyst for oxygen reduction reaction.

Originality/value

The combined method for synthesis of chlorinated iron phthalocyanine was novel and can find numerous applications in the industry, especially as an oxygen reduction reaction non-precious metal catalyst.

Details

Pigment & Resin Technology, vol. 46 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 1 April 1987

City Technology is one company that seems to know how to run a sensor manufacturing business, as Stephen McClelland explains.

Abstract

City Technology is one company that seems to know how to run a sensor manufacturing business, as Stephen McClelland explains.

Details

Sensor Review, vol. 7 no. 4
Type: Research Article
ISSN: 0260-2288

Article
Publication date: 15 June 2010

Kaushik Alayavalli and David L. Bourell

The purpose of this paper is to produce electrically conductive, fluid impermeable graphite bipolar plates for a direct methanol fuel cell, using indirect selective laser…

Abstract

Purpose

The purpose of this paper is to produce electrically conductive, fluid impermeable graphite bipolar plates for a direct methanol fuel cell, using indirect selective laser sintering (SLS) and suitable post processing techniques.

Design/methodology/approach

Bipolar plates are made by the indirect SLS of graphite powder and phenolic resin mixture. The phenolic resin binder is then burnt off at a high temperature in a vacuum furnace to produce a 100 per cent carbon part. This brown part is then infiltrated using a low‐viscosity (∼5‐10  cps) cyanoacrylate to seal up the open pores, rendering the plates fluid impermeable.

Findings

It has been found that the electrical conductivity increases significantly (> 220 S/cm) with a corresponding increase in pyrolyzing temperature which correlates well with literature on the carbonization of phenol formaldehyde resins. The cyanoacrylate infiltrated parts tested under fluid pressure demonstrated no leakage through the plate, indicating full closure of open porosity.

Originality/value

This work demonstrates the capability of the SLS process to produce working bipolar plates with complex flow field designs that can be tested to verify its efficacy in a working fuel cell, thereby saving time and cost in machining natural graphite.

Details

Rapid Prototyping Journal, vol. 16 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 16 October 2023

Reetu Yadav, Mamta Kushwah, Anna Nikolaevna Berlina and Mulayam Singh Gaur

The purpose of this study is determination of cadmium using silver-gold bimetallic nanoparticles (Ag-Au BMNPs) and an aptamer modified glassy carbon electrode.

Abstract

Purpose

The purpose of this study is determination of cadmium using silver-gold bimetallic nanoparticles (Ag-Au BMNPs) and an aptamer modified glassy carbon electrode.

Design/methodology/approach

The maximum response of modified electrode was obtained with, 50 mV pulse amplitude, 20 mV/s scan rate in phosphate buffer of pH 4.0. Ag-Au BMNPs, as the mediators improved electron transmit during the entire electron transfer process and the aptasensor response. Herein, the authors used aptamer as the capture probe to prepare an aptasensor with enhanced stability.

Findings

The proposed aptasensor exhibited a wide linearity to cadmium in the range of 0.001–0.100 µg/L with a low detection limit of 0.005×10−3 µg/L. The glassy carbon electrodes with Ag-Au BMNPs showed a lower detection limit.

Originality/value

This aptasensor has good reproducibility, stability and repeatability and is cost-effective to regenerate. The specificity and selectivity of the novel modified electrode is tested in the presence of other interfering metal ions such as Fe2+, Mn2+, Mg2+, Sb3+ and Bi3+. The aptasensor shows 10 times more sensitivity and selectivity for Cd2+ ions.

Details

Sensor Review, vol. 43 no. 5/6
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 11 April 2022

Hadeel Alhazimeh, Mohamed Ghazi Al-Fandi and Lina M.K. Al-Ebbini

Ascorbic acid (AA) is an essential vitamin for human health. Therefore, fast and cost-effective detecting of AA is essential, whether in human or food samples. The purpose of this…

Abstract

Purpose

Ascorbic acid (AA) is an essential vitamin for human health. Therefore, fast and cost-effective detecting of AA is essential, whether in human or food samples. The purpose of this paper is to develop an electrochemical nanosensor for AA detection.

Design/methodology/approach

The proposed nanosensor was developed by printing carbon nanoparticles ink and silver nanoparticles ink on a polydimethylsiloxane (PDMS) substrate. The surface of the PDMS substrate was first treated by corona plasma. Then, the nanomaterials printer was used to deposit both inks on the substrate. The working electrode surface was modified by drop-casting of carbon nanotubes. Morphological evaluation was applied using scanning electron microscopy and cyclic voltammetry. Also, a potentiostat was used to detect AA by differential pulse voltammetry.

Findings

It has been shown that the developed nanosensor linearly worked at a range of (0–5 mM), with a limit of detection lower than 0.8 mM and a relative standard deviation of 6.6%.

Originality/value

The developed nanosensor is characterized by a simple and cost-effective sensing tool for AA. In particular, the nanomaterials enhanced the nanosensor’s sensitivity due to the high catalytic activity.

Details

Sensor Review, vol. 42 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 12 March 2021

Hamed Dabaghi, Saeid Saieda Ardakani and Seyed Mohammad Tabataba’i-Nasab

The purpose of this paper is to focus on the emerging phenomenon of medical tourism in the context of Iran from a customer experience management perspective and benchmark of their…

Abstract

Purpose

The purpose of this paper is to focus on the emerging phenomenon of medical tourism in the context of Iran from a customer experience management perspective and benchmark of their judgment including positive or negative, of the experience they have achieved of the Iranian health (medical) experience (CE) and suggest scenarios for the improvement of the Iranian customer experience management (CEM).

Design/methodology/approach

The research methodologies and research methods that are used in this descriptive-analytical research are based on an inspection of the remarkable literature related to medical tourism and customer experience management. The data gathering instrument is a researcher-made questionnaire based on the variables in the conceptual model extracted from the research literature. The study was conducted from May to August 2019. The population cohort of this study was the foreign patients calling selected Iranian hospitals and the sampling method was a purposive and snowball sample of prospective medical tourists. As the study was conducted throughout Iran, some important hospitals in Iran were selected by stratified sampling Yang et al. (2020b). The sample size and data saturation were 500 participants Lv and Song (2019). The collected data using the questionnaire were analyzed by SPSS software and statistical tests.

Findings

According to the results, the customer experience management statistical significance in the task aspect is (p = 0.0523), in the mechanical aspect is (p = 0.0563), in the human aspect is (p = 0.0544). The study showed positive customer experience among the patients who had been treated in the Iranian hospitals.

Originality/value

There is a lack of study that focuses on medical tourism and customer experience management in Iran. Therefore, based on the results of this study, the experience of medical tourists in Iran proved to be positive and satisfying. As little research has been conducted in the area of customer experience management (CEM) in Iranian medical tourism, future researchers can use these valuable results precisely and in more detail to benchmark more accurately the customer experience in all areas of medical and health tourism and other research areas in different aspects of CEM in Iran.

Details

Journal of Islamic Marketing, vol. 13 no. 1
Type: Research Article
ISSN: 1759-0833

Keywords

1 – 10 of 31