Silver Nanorod Array Electrodes and their Application for Detection of Low Concentration Chloropropanol in Aqueous Media

2014 ◽  
Vol 697 ◽  
pp. 136-139
Author(s):  
Li Sun ◽  
Zhi Gang Yuan ◽  
Wen Bang Gong ◽  
Zi Li Xu ◽  
Ji Jun Lu ◽  
...  

Silver nanorod array electrodes were prepared by a facile method. The characters of silver nanorod arrays were tested by SEM and XRD. The electrochemical activity of this electrode was tested in the 0.1 mol/L NaClO4aqueous solution using chloropropanol as analyte by electrochemical methods. The results of cyclic voltammetry show that silver nanorod array electrodes are good detector for low concentration chloropropanol in aqueous media and display a distinct reduction peak. It is more sensitivity than the bulk Ag electrode. Cyclic voltammetry and Warburg impedance measurements show that the action process between electrode and chloropropanol was controlled by the diffusion and the reaction is totally irreversible. In short, silver nanorod array electrodes show great potential in the determination of trace chloropropanol.

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 525
Author(s):  
Anna M. Brudzisz ◽  
Agnieszka Brzózka ◽  
Grzegorz D. Sulka

Herein, we report, for the first time, a comparative study on the electrocatalytic reduction of chloroform on silver in different aqueous supporting electrolytes. Cyclic voltammetry measurements were performed at a wide range of scan rates and concentrations of CHCl3 using 0.05 M NaClO4, NaH2PO4, and Na2HPO4 as supporting electrolytes. We observed that a type of supporting electrolyte anion strongly influences both the potential as well as the current density of the chloroform reduction peak, mainly due to the presence of OH− in an alkaline Na2HPO4 solution, which is a specifically interacting anion. Moreover, the highest sensitivity of the Ag electrode toward CHCl3 reduction was observed in a neutral NaClO4 aqueous solution. It was found that the electroreduction of chloroform at the silver surface occurs via a concerted mechanism regardless of the type of the studied supporting electrolyte.


2013 ◽  
Vol 17 (06n07) ◽  
pp. 447-453 ◽  
Author(s):  
Hiroaki Isago ◽  
Harumi Fujita

Dissociation of imino proton(s) in the cavity of the macrocycle of a highly water-soluble, metal-free phthalocyanine ( H 2( H 4 tsppc ); where H 4 tsppc denotes tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxy}phthalocyaninate) in ethanolic and aqueous solutions has spectrophotometrically been investigated. The spectral changes associated with reaction with NaOH have been found to involve one-proton transfer process in aqueous media while two-protons process in ethanolic media. The acid-dissociation constant of the first imino proton in water (in the presence of Triton X-100) has been determined to be 12.5 ± 0.2 (as pKa) at 25 °C. The doubly deprotonated species in EtOH has been easily converted to its corresponding cobalt(II) derivative by thermal reaction with anhydrous CoCl 2.


2020 ◽  
Vol 20 (6) ◽  
pp. 3512-3518
Author(s):  
Saleh Khan ◽  
Xiao-He Liu ◽  
Xi Jiang ◽  
Qing-Yun Chen

Highly efficient and effective porous ZnO nanorod arrays were fabricated by annealing ZnO nanorod arrays grown on a substrate using a simple hydrothermal method. The annealing had a positive effect on the nanorod morphology, structure and optical properties. The porosity was closely related to the annealing temperature. After heating at 450 °C, pores appeared on the nanorods. It was demonstrated that the porosity could be exploited to improve the visible light absorption of ZnO and reduce the bandgap from 3.11 eV to 2.99 eV. A combination of improved charge separation and transport of the heat-treated ZnO thus led to an increase in the photoelectrochemical properties. At an irradiation intensity of 100 mW/cm−2, the photocurrent density of the porous nanorod array was approximately 1.3 mA cm−2 at 1.2 V versus Ag/AgCl, which was five times higher than that of the ZnO nanorods. These results revealed the synthesis of promising porous ZnO nanorods for photoelectrochemical applications.


The Analyst ◽  
1997 ◽  
Vol 122 (12) ◽  
pp. 1543-1547 ◽  
Author(s):  
Gerardo Piñeiro Avila ◽  
Miguel de la Guardia
Keyword(s):  

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fernanda Ramos de Andrade ◽  
Renata Alves de Toledo ◽  
Carlos Manoel Pedro Vaz

An electroanalytical methodology was developed for the direct determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using a graphite-polyurethane composite electrode and square wave voltammetry (SWV). 2,4-D exhibited one reduction peak with characteristics of an irreversible process at −0.54 V (versus Ag/AgCl), which is controlled by the diffusion of the reagent on the electrode surface. After the experimental parameters optimization (pH 2.0,f=50 s−1,a=0.50 V, andΔEi=0.03 V), analytical curves were constructed in the range of 0.66 mg L−1to 2.62  mg L−1. Detection (LD) and quantification (LQ) limits were 17.6 μg L−1and 58.6 μg L−1, respectively. The methodology was successfully applied to measure the percolation of the herbicide 2,4-D in undisturbed soil columns of different granulometric compositions.


The Analyst ◽  
1984 ◽  
Vol 109 (2) ◽  
pp. 123-125 ◽  
Author(s):  
José Aznárez ◽  
Francisco Palacios ◽  
Maria S. Ortega ◽  
Juan Carlos Vidal

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