Effect of the surface roughness of conducting polypyrrole thin‐film electrodes on the electrocatalytic reduction of nitrobenzene

Abstract

Conducting polypyrrole (PPy) thin‐film electrodes were prepared by the electropolymerization of pyrrole on gold‐coated glass plates. Films of various roughnesses were obtained by the variation of the scan rates during electropolymerization. These thin films were modified by doping with 6mM of the dopant NiCl2. The surface morphology of the films was studied by scanning electron microscopy and atomic force microscopy (AFM), which suggested films prepared with a high scan rate were rougher in nature than the films produced with a low scan rate. The electrocatalytic reduction of nitrobenzene was carried out with these electrodes with the cyclic voltammetry technique in acetonitrile containing 0.1M HClO4 as a supporting electrolyte. The various results obtained show that the conducting PPy thin‐film electrodes were catalytically active toward the electroreduction process. The modified PPy film electrodes doped with NiCl2 were more active toward nitrobenzene electroreduction than the PPy film alone. The results indicate that the roughness of the films played a very important role in determining their catalytic activity. The PPy films that were more rough in nature were catalytically more active than the smooth films; this may have been due to the availability of more reactive sites in the case of rough films. The apparent diffusion coefficients of the PPy film electrodes were also calculated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

A New Class of Zn1‐xFex–Oxyselenide and Zn1‐xFex–LDH Nanostructured Material with Remarkable Bifunctional Oxygen and Hydrogen Evolution Electrocatalytic Activities for Overall Water Splitting

“…root‐mean‐square roughness ( R q ), average roughness ( R a ) and ten‐points mean roughness ( R z ), and a maximum deviation of Zn 1‐ x Fe x –LDH and Zn 1‐ x Fe x –oxyselenide were estimated from AFM data and are given in Table S1 (Supporting Information). From the obtained AFM data, it is observed that the nanosheets after selenization were rougher than the Zn 1‐ x Fe x –LDH nanosheet . Since the electrophysical–chemical properties of the material are strongly dependent on surface roughness, the as‐synthesized materials are expected to show distinct catalytic activities …”

“…From the obtained AFM data, it is observed that the nanosheets after selenization were rougher than the Zn 1-x Fe x -LDH nanosheet. [47,48] Since the electrophysical-chemical properties of the material are strongly dependent on surface roughness, the as-synthesized materials are expected to show distinct catalytic activities. [49] Further, in order to get better insights into the structuralrelated information, high-resolution transmission electron microscope (HR-TEM) was carried out.…”

Porphyrin-Conjugated Microporous Polymer Nanospheres as Electrocatalysts for Nitrobenzene Detection and Oxygen Evolution Reaction

“…Thus, detection and disposal of toxic and hazardous waste nitrobenzene have received a great deal of attention. For the reduction and treatment of nitrobenzene to aniline, many catalysts have been developed, including Ru nanoparticles, PdO/CuO nanoparticles, AuPt bipyramid nanoframes, AgAu Alloy nanodots, Cu–Zr amorphous alloys, Cu nanoparticles, and organic polymers. ,− However, most of these catalysts are metal-based or even precious-metal-based materials, and the high prices limit their wide application. As a result, it is crucial to develop cheap and easily available catalysts for the reduction of nitrobenzene.…”

Electrochemical Deposition of Polypyrrole in the Presence of Silanes as Adhesion Promoters

“…However, the poor adhesion of PPy to the substrate or electrode is usually the main problem. Several methodologies have been studied to increase electrode–PPy adhesion, such as electrode functionalization [ 12 , 13 , 14 ], optimization of the polymerization parameters [ 9 , 15 ], and adhesion promoters [ 16 , 17 , 18 ]. Alkoxysilanes are a group of compounds that have been used for a long time as adhesion promoters between inorganic surfaces and polymeric matrixes [ 19 ].…”