POLYPYRROLE COATED CELLULOSIC SUBSTRATE MODIFIED BY COPPER OXIDE AS ELECTRODE FOR NITRATE ELECTROREDUCTION

2015 ◽  
Vol 22 (05) ◽  
pp. 1550065 ◽  
Author(s):  
A. HAMAM ◽  
D. OUKIL ◽  
A. DIB ◽  
H. HAMMACHE ◽  
L. MAKHLOUFI ◽  
...  
Keyword(s):  
Copper Oxide ◽  
Nitrate Reduction ◽  
Electrochemical Impedance ◽  
Nitrate Concentration ◽  
Film Surface ◽  
Xrd Analysis ◽  
Electrochemical Reactivity ◽  
Cellulosic Substrate ◽  
Oxide Particles ◽  
Cyclic Voltamperometry

The aim of this work is to synthesize polypyrrole (PPy) films on nonconducting cellulosic substrate and modified by copper oxide particles for use in the nitrate electroreduction process. Firstly, the chemical polymerization of polypyrrole onto cellulosic substrate is conducted by using FeCl 3 as an oxidant and pyrrole as monomer. The thickness and topography of the different PPy films obtained were estimated using a profilometer apparatus. The electrochemical reactivity of the obtained electrodes was tested by voltamperometry technique and electrochemical impedance spectroscopy. Secondly, the modification of the PPy film surface by incorporation of copper oxide particles is conducted by applying a galvanostatic procedure from a CuCl 2 solution. The SEM, EDX and XRD analysis showed the presence of CuO particles in the polymer films with dimensions less than 50 nm. From cyclic voltamperometry experiments, the composite activity for the nitrate electroreduction reaction was evaluated and the peak of nitrate reduction is found to vary linearly with initial nitrate concentration.

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

Green synthesized copper oxide nanostructures for potential multifaceted biomedical applications

2021 ◽  
Author(s):  
R. L. Kalyani ◽  
Sarath Chandra Veerla ◽  
Venkata Ramana Murthy Kolapalli ◽  
Vijay Kumar P.P.N. ◽  
V. Swamy P. ◽  
...  
Keyword(s):  
Copper Oxide ◽  
Green Synthesis ◽  
Biomedical Applications ◽  
Leaf Extract ◽  
Capping Agent ◽  
Annona Squamosa ◽  
Oxide Nanostructures ◽  
Oxide Particles

In the present study, Annona squamosa leaf extract was used as a reducing and capping agent for the facile green synthesis of nano-copper oxide particles. The optical, structural and morphological...

Tribological Investigation of Copper (Cu) and Copper Oxide (CuO) Nanoparticles Based Nanolubricants for Machine Tool Slideways

2014 ◽  
Author(s):  
Saravanakumar Nesappan ◽  
Nallasamy Palanisamy ◽  
Mahesh Chandran
Keyword(s):  
Electron Microscope ◽  
Machine Tool ◽  
Copper Oxide ◽  
Elevated Temperatures ◽  
Stick Slip ◽  
Base Oil ◽  
Weight Composition ◽  
The Coefficient Of Friction ◽  
Oxide Particles ◽  
Mineral Lubricant

The present study intends to evaluate the tribological characteristics of Copper (Cu) and Copper oxide (CuO) based nanolubricant for its use in machine tool slideways. Different sizes of copper and copper oxide particles were chosen and physical characterisation were carried out using scanning electron microscope (SEM) and transmission electron microscope (TEM). The nanolubricants were prepared by adding various proportions (0.1%, 0.25%, 0.4% wt) of the particles in Polyalphaolefin (PAO) base oil with lecithin and oleic acid surfactants. Friction and stick-slip characteristics of the nanolubricants were assessed using pin-on-block reciprocating friction monitor simulating the actual loading conditions prevailing in machine tool slideways. Studies were also conducted under elevated temperatures to ascertain the performance of particles at higher temperatures. Extreme pressure properties of the lubricants were studied using Four Ball Tester. The results of the experiments were compared with ISO VG 32 oil, a conventional mineral lubricant meant for machine tool slideways and it was found that the tribological properties nanolubricants using both the nanoparticles were considerably better. The coefficient of friction found to be decreased by 2.5% and 17.5% for copper particles with 0.1% weight composition in ambient temperature and elevated temperature respectively. Whereas for copper oxide particles with 0.1% weight composition a reduction of 14.25% and 10% were obtained.

Wood derived biochar as electron donor and its influence on microbial denitrification: Role of extracellular polymeric substances in extracellular electron transfer

2020 ◽  
Author(s):  
Kuppusamy Sathishkumar ◽  
Yi Li ◽  
Rana Muhammad Adnan Ikram
Keyword(s):  
Electron Transfer ◽  
Electron Donor ◽  
Electrochemical Behavior ◽  
Nitrate Reduction ◽  
Extracellular Polymeric Substances ◽  
Electrochemical Impedance ◽  
Electrochemical Analysis ◽  
Extracellular Electron Transfer ◽  
Microbial Denitrification

<p>Biochar is extensively used in environmental pollutant remediation because of its diverse property, however the effect of biochar on microbial nitrate reduction and electrochemical behavior of biochar remain unknown. Also electron transfer from the microbial cells to electron donor or acceptor have been transport across the extracellular polymeric substances (EPS), however it was unclear whether extracellular polymeric substances captured or enhance the electrons.  Hence, aim of the present study is to investigate the electrochemical behavior of biochar and its effects on microbial nitrate reduction and elucidate the role of extracellular polymeric substances in extracellular electron transfer (EET).  The biochar was prepared at different pyrolysis temperatures (400 °C, 500 °C and 600 °C) and their electrochemical behavior was characterized by electrochemical analysis (cyclic voltammetry, electrochemical impedance spectrum, chronoamperometry). Results demonstrated that all the biochars could donate and accept the electrons, impact of biochar on microbial nitrate reduction was studied and the results showed that biochar prepared at 400 °C significantly enhances microbial nitrate reduction process. Phenol O-H and quinone C=O surface functional groups on the biochar contributes in the overall electron exchange which accelerated the nitrate reduction. The role of EPS in EET by electrochemical analysis results reveals that outer membrane c-type cytochrome and flavin protein from the biofilm was involved in electron transfer process, and EPS act as transient media for microbial EET. Overall, present study suggested that biochar could be used as eco-friendly material for the enhancement of microbial denitrification.</p>

Evaluation of Copper Oxide to Copper Selectivity of Chemical Systems for BEOL Cleaning Through Electrochemical Investigations

2007 ◽  
Vol 990 ◽  
Author(s):  
Nandini Venkataraman ◽  
Ashok Kumar Muthukumaran ◽  
Srini Raghavan
Keyword(s):  
Copper Oxide ◽  
Electrochemical Impedance ◽  
Oxide Films ◽  
Ammonium Phosphate ◽  
Reduction Technique ◽  
Impedance Spectra ◽  
Electrochemical Impedance Spectra ◽  
Fundamental Study ◽  
Chemical Systems ◽  
Oxide Dissolution

ABSTRACTBack End of Line (BEOL) cleaning of copper based structures requires chemical formulations that can remove copper oxide selectively without corroding copper and etching the dielectric. Many commercially available semi-aqueous and all aqueous formulations claim to meet these criteria. These include semi-aqueous fluoride strippers (SAF) and all- aqueous ammonium phosphate based chemical systems.This paper will report the results from a fundamental study undertaken to evaluate the performance of a semi-aqueous fluoride formulation in removing copper oxide films of controlled thickness grown on copper. The thickness and composition of the oxide films were determined electrochemically using cathodic reduction technique. Electrochemical impedance spectra of samples immersed in the formulation have been measured as a function of time to follow copper oxide dissolution and the data have been analyzed to detect the transition of copper oxide to copper.

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