Fabrication and characterization of spinel Ni0.5Cu0.5Co2O4 nanoparticles as bi-functional catalysts for oxygen reduction and evolution reaction

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940060
Author(s):  
Jin Xiao ◽  
Lin Zhang ◽  
Jiabin Peng ◽  
Haitong Xue ◽  
Hongchun Yuan ◽  
...  

Developing efficient and low-cost bi-functional electrolytes for energy applications such as fuel cells and rechargeable metal-air batteries is highly desirable. Here, we have synthesized spinel Ni[Formula: see text]Cu[Formula: see text]Co2O4 (NCC) nanoparticles as nonprecious bi-functional electrocatalysts by a simple hydrothermal reaction method. The phase structure and the morphology of NCC nanoparticles have been investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) while the electrocatalytic activity of the samples has been studied in alkaline solution by using rotating disk electrode technique. The electrocatalysts have showed a comparable ORR and OER catalytic activities compared with of those of the other transition metal oxides, suggesting the feasibility of the NCC as the bi-functional electrolytes materials for ORR and OER.

2014 ◽  
Vol 22 (2) ◽  
pp. 135-144
Author(s):  
Gh. Nemtoi ◽  
Ig. Cretescu ◽  
Iuliana Breaban ◽  
P.C. Verestiuc ◽  
Oana-Maria Tucaliuc

Abstract This article presents some aspects related to the cathodic discharge of the mercuric ion provided from HgCl2 into an aqueous solution of 0.1 M H2SO4 on different types of electrodes: gold disc electrode (GDE), carbon paste electrode (CPE) and platinum-disk electrode (PDE). Using the rotating disk electrode technique applied on PDE it was established that the cathodic discharge mechanism for the mercuric ion is based on both process types: mass transport, achieved by diffusion and charge transfer, achieved by electron transfer from cathode to mercury ion


2010 ◽  
Vol 163 ◽  
pp. 64-67 ◽  
Author(s):  
Anna Góral ◽  
E. Bełtowska-Lehman ◽  
P. Indyka

In the present study, the electrodeposition of composites consisted of metal matrix (nickel) and inert particles (hard nano-sized Al2O3 oxide) has been carried out in a Watt’s type bath of pH 4, at room temperature in a system with the steel rotating disk electrode. The influence of dispersed Al2O3 powder on structure characteristics (morphology, phase composition, texture, residual stresses) of Ni/Al2O3 coatings has been investigated. The crystallographic texture of Ni and Ni/Al2O3 coatings deposited on the steel substrates was analyzed by XRD technique based on the back-reflection pole figures. The “sin2ψ” X-ray diffraction method was used to determine the residual stress as a function of X-ray penetration depth. The influence of Al2O3 particles on the value of the Ni coating microhardness was also analyzed.


1996 ◽  
Vol 451 ◽  
Author(s):  
S. D. Leith ◽  
D. T. Schwartz

ABSTRACTDescribed are results showing that an oscillating flow-field can induce spatially periodic composition variations in electrodeposited NiFe films. Flow-induced NiFe composition modulated alloys (CMA's) were deposited on the disk of a rotating disk electrode by oscillating the disk rotation rate during galvanostatic plating. Deposit composition and structure were investigated using potentiostatic stripping voltammetry and scanning probe microscopy. Results illustrate a linear relationship between the composition modulation wavelength and the flow oscillation period. CMA's with wavelengths less than 10 nm can be fabricated when plating with a disk rotation rate oscillation period less than 3 seconds.


NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850052
Author(s):  
Yuanyuan Zhou ◽  
Jianying Deng ◽  
Shimei Li ◽  
Zefeng Li

Core–shell Cu@Ni chains were successfully synthesized through a mild hydrothermal reaction. The morphology, structure and microwave electromagnetic properties of the composite were then characterized by X-ray diffraction, energy-dispersive spectroscopy, scanning electron microscopy and vector network analysis. The formation mechanisms of the core–shell structure and one-dimensional chains were ascribed to the varying redox potentials of Cu and Ni ions and the magnetic dipole–dipole attraction. Furthermore, a minimal reflection loss (RL) of [Formula: see text]20.7[Formula: see text]dB was observed at 9.6[Formula: see text]GHz with a thickness of 2.0[Formula: see text]mm and the effective absorption ([Formula: see text]10[Formula: see text]dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2[Formula: see text]GHz and 16.6[Formula: see text]GHz for the thin absorber thickness of 2.0–4.0[Formula: see text]mm. The novel core–shell chain-like Cu@Ni alloy can be used as a promising absorbing material because it shows numerous features such as thin thickness, strong absorption, low cost and lightweight.


2005 ◽  
Vol 900 ◽  
Author(s):  
Peter N. Njoki ◽  
Jin Luo ◽  
Aisley Jacob ◽  
Rizwan Munawar ◽  
Bilal Khan ◽  
...  

ABSTRACTThe ability to control composition and size in the synthesis of bimetallic nanoparticles is important for the exploitation of the bimetallic catalytic properties. This paper reports recent findings of an investigation of the synthesis of gold-platinum (AuPt) bimetallic nanoparticles in aqueous solution via reduction of AuCl4− and PtCl42− using a combination of reducing and capping agents. In addition to characterization of the morphological properties of the AuPt nanoparticles using TEM and XRD, the electrocatalytic activity of the carbon-supported AuPt nanoparticle catalysts was also examined for oxygen reduction reaction (ORR) using the rotating disk electrode (RDE) technique. The findings have implications to the design of bimetallic nanoparticle catalysts for fuel cell reactions.


2012 ◽  
Vol 60 (1) ◽  
pp. 137-140 ◽  
Author(s):  
RI Chowdhury ◽  
MS Islam ◽  
F Sabeth ◽  
G Mustafa ◽  
SFU Farhad ◽  
...  

Cadmium selenide (CdSe) thin films have been deposited on glass/conducting glass substrates using low-cost electrodeposition method. X-ray diffraction (XRD) technique has been used to identify the phases present in the deposited films and observed that the deposited films are mainly consisting of CdSe phases. The photoelectrochemical (PEC) cell measurements indicate that the CdSe films are n-type in electrical conduction, and optical absorption measurements show that the bandgap for as-deposited film is estimated to be 2.1 eV. Upon heat treatment at 723 K for 30 min in air the band gap of CdSe film is decreased to 1.8 eV. The surface morphology of the deposited films has been characterized using scanning electron microscopy (SEM) and observed that very homogeneous and uniform CdSe film is grown onto FTO/glass substrate. The aim of this work is to use n-type CdSe window materials in CdTe based solar cell structures. The results will be presented in this paper in the light of observed data.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10352  Dhaka Univ. J. Sci. 60(1): 137-140 2012 (January)


2018 ◽  
Vol MA2018-01 (31) ◽  
pp. 1927-1927
Author(s):  
Mahfouz Ali Saeed

Cu2(ZnSn)(S)4 (CTZS) has number of advantages over other solar this film such as CuInGaSe2 (CIGS) due to its higher band gap. Generating such thin film layers by electrochemical methods is particularly attractive because the lower generating budget and the higher throughput. According to literature it is default with many challenges to produce CTZS from electrodeposition methods due to wide range of standard potential of each elements of CTZS 1-4. Sulfur atomic ratio is about 50% of CTZS alloy which add more complexity to electrochemical processing. We introduce in this work electropulsing techniques on order to electroplate at transient current instead of steady state current. Electrolyte composition was similar to dilute concentration from the previous work which is is considerably more dilute in comparison to conventional electrolytes used in the literature1-4. The bath composition is: 0.0042 M CuSO4, 0.0031 M ZnSO4, 0.035 M SnCl2, 0.005 M Na2S2O3, and 0.045 M Na2S2O3. PHydrion is used to buffer the electrolyte to pH=2, and supporting electrolyte is 0.6 M LiCl. Experiments was conducted at a rotating disk electrode which offers measureable characterization of the rotating flow at room temperature. Electrochemical pulsing current behavior study at different off and on time and current in Fig. 1 and 2. The effects of pulsing time and current density on the CTZS thin film adhesion and atomic composition are discussed. The annealing was carried out on tube furnace under sulfur element atmosphere with no extra material addition. The amount of sulfur on the absorber layer was optimized. The alloy composition was examined using Energy-dispersive X-ray spectroscopy technique (EDS) Fig. 2. XRD analysis method used to characterized CTZS thickness and crystallography. Figure 1


2014 ◽  
Vol 895 ◽  
pp. 147-150 ◽  
Author(s):  
Nur Ain Ibrahim ◽  
Noriean Azraaie ◽  
Nurul Aimi Mohd Zainul Abidin ◽  
Nur Amira Mamat Razali ◽  
Fauziah Abdul Aziz ◽  
...  

The main component in natural fibre is cellulose (C6H10O5)n. Cellulose from agricultural by-product is abundant, low cost, eco-friendly, biodegradable, and renewable. This research work was prepared alpha cellulose from pineapple leaf fibre (PALF), which obtained from the leaves of pineapple plant, Ananas comosus belonged to the family Bromeliaceae. The treated and untreated samples were characterized using X-ray diffraction (XRD).


Sign in / Sign up

Export Citation Format

Share Document