scholarly journals Investigation of a Cu/Pd Bimetallic System Electrodeposited on Boron-Doped Diamond Films for Application in Electrocatalytic Reduction of Nitrate

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Jorge T. Matsushima ◽  
Valéria C. Fernandes ◽  
Andrea B. Couto ◽  
Maurício R. Baldan ◽  
Neidenêi G. Ferreira

The Cu/Pd bimetallic system electrodeposited on boron-doped diamond (BDD) films for application, as electrode material in the electrochemical reduction of nitrate was studied. The electrochemical behavior of Cu, Pd, and Cu/Pd bimetallic system was evaluated by cyclic voltammetry. From these results, the formation of the Cu/Pd composite was verified. In addition, Cu with different phases and a Cu/Pd phase in the composite were obtained. Morphological analysis by scanning electron microscopy (SEM) revealed a homogeneous distribution of Cu/Pd bimetallic particles with intermediary dimensions compared to those observed in Cu or Pd electrodeposits separately. These composites were tested as electrocatalysts for nitrate reduction in Britton-Robinson buffer solution (pH 9). Electrochemical measurements showed that composites with higher Cu content displayed the best electrocatalytic activity for nitrate reduction, and the Cu/Pd phase in the bimetallic system served to improve the Cu adherence on BDD electrode.

2013 ◽  
Vol 1511 ◽  
Author(s):  
Jorge T. Matsushima ◽  
Andrea B. Couto ◽  
Neidenei G. Ferreira ◽  
Mauricio R. Baldan

ABSTRACTThis paper presents the study of the electrochemical deposition of Cu/Sn alloy nanoparticles on Boron Doped Diamond (BDD) films in order to improve their electrocatalytic activity and selectivity for application in nitrate electrochemical reduction. Cyclic voltammetry measurements evidenced the formation of Cu/Sn alloy electrodeposited on BDD electrode. The electrodeposited Cu/Sn can be better visualized by analyzing the dissolution process. By studying the dissolution peak separately, the dissolution peak of the Sn was obtained at a more positive potential, when compared with the dissolution peak of Cu. From the scanning electronic microscopy (SEM) analysis, the homogeneous distribution of the Cu/Sn alloys particles on BDD surface with grain size in nanometric scale was verified. From X-ray diffraction analysis, two Cu/Sn alloy phases (Cu41Sn11 and Cu10Sn3) were identified for the electrodeposits obtained at -0.5V and charge of 0.26 C. The electrocatalytic reduction of nitrate in 0.1 M Britton-Robinson (BR) buffer solution with pH 9 was analyzed. The BDD electrode modified with Cu/Sn alloy nanoparticles proved to potentiate the electrocatalytic reduction of nitrate.


2012 ◽  
Vol 1395 ◽  
Author(s):  
A. B. Couto ◽  
M. R. Baldan ◽  
N. G. Ferreira

ABSTRACTPhotoelectrodeposition of copper on boron-doped diamond films (BDD) was investigated. In this work, two different doped films were analyzed. Copper particles were deposited in the potentiostat mode and under UV irradiation. The BDD film as-grown and the BDD film modifed with Cu (Cu/BDD) on the surface were characterized by Raman Spectroscopy and Scanning Electron Microscopy (SEM) respectivily. These electrodes were tested as electrocatalysts for nitrate reduction in Britton-Robinson buffer solution (pH=3). Electrochemical measurements showed that the electrode with high doping level displayed the best electrocatalytic activity.


2021 ◽  
Vol 40 (1) ◽  
pp. 11
Author(s):  
Ertuğrul Keskin ◽  
Shabnam Allahverdiyeva ◽  
Amer Alali ◽  
Yavuz Yardım

The present work describes a simple, fast, and inexpensive voltammetric method for diflunisal measurement using a non-modified boron-doped diamond (BDD) electrode. The oxidation of the agent was irreversible and presented a diffusion‐controlled process. The sensitivity of the square wave voltammetric measurements were significantly improved when the cationic surfactant, cetyltrimethylammonium bromide (CTAB), was present in the supporting electrolyte solution. Using square-wave mode, a linear response was obtained for diflunisal quantification in 0.1 mol L-1 phosphate buffer solution (pH 2.5) solution containing 5×10-5 mol L-1 CTAB at +1.07 V (vs. Ag/AgCl) (after 30 s accumulation under open-circuit conditions). Linearity was found for 0.05 to 2.0 μg mL-1 (2.0×10-7-8.0×10-6 mol L-1) with a detection limit 0.013 μg mL-1 (5.2×10-8 mol L-1). The developed approach could be used for the quantification of diflunisal in pharmaceutical formulations.


2016 ◽  
Vol 9 (2) ◽  
pp. 146-151 ◽  
Author(s):  
Kristína Cinková ◽  
Dana Andrejčáková ◽  
Ľubomír Švorc

Abstract This paper presents an electrochemical behavior study and quantification of fluoroquinolone antibiotic ciprofloxacin using boron-doped diamond electrode. Ciprofloxacin provides a diffusion-driven electrode reaction with an irreversible and poorly defined peak at +1.6 V vs. Ag/AgCl electrode in the presence of Britton-Robinson buffer solution pH 4. Applying differential pulse voltammetry (modulation amplitude of 60 mV, modulation time of 50 ms), the calibration curve with high linearity (R2 = 0.997) was obtained within the concentration range of (0.74 – 20.0) × 10−6 mol L−1 with the detection limit of 6.0 × 10−7 mol L−1 and repeatability expressed by relative standard deviation of 2.7 % (for 20 measurements). Interference study was performed to explore the selectivity of the elaborated procedure. By analysis of pharmaceutical dosages and model human urine samples, the ciprofloxacin content with the recovery values ranging from 88.4 to 121.2 % were determined. The developed approach using point-of-care electrochemical sensor based on boron-doped diamond material could represent inexpensive analytical alternative to separation methods and could be beneficial in analysis of biological samples and in the quality control in pharmaceutical industry.


2015 ◽  
Vol 98 (6) ◽  
pp. 1535-1541 ◽  
Author(s):  
Biljana Nigović ◽  
Ana Mornar ◽  
Mario Završki

Abstract A boron-doped diamond electrode provided a sensitive and cost-effective sensing platform for detection and quantitative determination of novel beta(1)-adrenergic receptor antagonist nebivolol. The net square-wave voltammetric response at 1.31 V related to the oxidation of nebivolol was obtained in Britton-Robinson buffer solution at pH 8. It increased linearly with the drug concentration in the range of 2.5 × 10–7 to 1.5 × 10–5 M. The LOD attained was 3.2 × 10–8 M. The practical analytical approach was illustrated by high speed quantification of nebivolol in a commercial pharmaceutical formulation. The RP-HPLC was selected as a comparative method for evaluating the proposed electroanalytical method. The newly developed method at the unmodified electrode surface was faster and simpler in comparison with HPLC (the retention time was 17.6 min), and only 6 s was necessary for direct voltammetric measurement in the potential range from 0.5 to 1.7 V with a 2 mV potential step and pulse frequency of 100 Hz.


2015 ◽  
Vol 39 (2) ◽  
pp. 553-562 ◽  
Author(s):  
Camila Prado Cenciani de Souza ◽  
Cleide Aparecida de Abreu ◽  
José Francisco da Cunha ◽  
Geraldo Magela da Costa ◽  
Cristiano Alberto de Andrade

Alternative copper (Cu) sources could be used in fertilizer production, although the bioavailability of copper in these materials is unknown. The objective of this study was to evaluate the extractants neutral ammonium citrate (NAC), 2 % citric acid, 1 % acetic acid, 10 % HCl, 10 % H2SO4, buffer solution pH 6.0, DTPA, EDTA, water, and hot water in the quantification of available Cu content in several sources, relating them to the relative agronomic efficiency (RAE) of wheat grown in a clayey Latossolo Vermelho eutrófico (Oxisol) and Neossolo Quartzarênico (Typic Quartzipsamment). Copper was applied at the rate of 1.5 mg kg-1 as scrap slag, brass slag, Cu ore, granulated copper, and copper sulfate. The extractants 10 % HCl, 10 % H2SO4, and NAC extracted higher Cu concentrations. The RAE values of brass slag and Cu ore were similar to or higher than those of Cu sulfate and granulated Cu. Solubility in the 2nd NAC extractant, officially required for mineral fertilizers with Cu, was lower than 60 % for the scrap slag, Cu ore, and granulated copper sources. This fact indicates that adoption of the NAC extractant may be ineffective for industrial by-products, although no extractant was more efficient in predicting Cu availability for wheat fertilized with the Cu sources tested.


2021 ◽  
Vol 114 ◽  
pp. 108310
Author(s):  
Peijing Kuang ◽  
Keisuke Natsui ◽  
Yasuaki Einaga ◽  
Chuanping Feng ◽  
Yubo Cui ◽  
...  

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