Materials Letters

(1)

Electroless copper deposition on epoxy glass substrate for electrocatalysis of formaldehyde

Charif Dehchar

^a,b,^⇑

, Imene Chikouche

^c

, Rochdi Kherrat

^b

, Ali Sahari

^c

, Ahmed Zouaoui

^c

, Abdenacer Merati

^d

aResearch Center in Industrial Technologies CRTI, P.O. Box 64, Cheraga 16014, Algiers, Algeria

bLaboratory of Environmental Engineering, Badji Mokhtar University, Annaba, Algeria

cLaboratoire Croissance et Caractérisation de Nouveaux Semi-Conducteurs, Université Ferhat Abbas, Sétif-1, Algeria

dLaboratory of Electrochemistry and Corrosion, Polytechnic Military School, Algiers, Algeria

a r t i c l e i n f o

Article history:

Received 18 April 2018

Received in revised form 12 June 2018 Accepted 20 June 2018

Available online 21 June 2018

Keywords:

Copper

Electroless plating Formaldehyde Oxidation Thin films

a b s t r a c t

In this paper, we investigated the characteristics of a structured copper (Cu) film deposited on the surface of an insulating epoxy glass (EG) substrate via a facile electroless plating process. The film produced by this method was found to be of high purity and has a homogeneous microstructure consisting of an assembly of numerous aggregates that vary in size from 1 to 5mm depending on the electroless deposition time. The electrocatalytic activity of the prepared electrode was investigated for the electrooxidation of formaldehyde using cyclic voltammetry in 0.1 M NaOH solution. Results show that formaldehyde oxidation takes place at a low potential of0.34 V with large anodic current densities.

1. Introduction

Formaldehyde is an important industrial chemical used chiefly as a disinfectant and preservative and in chemical synthesis. It is encountered in many sectors like wood industry, health and food industries[1]. Unfortunately, it has been shown to cause serious adverse health effects with long-term use[2]. Consequently, con- trolling the effects of formaldehyde becomes increasingly important. The oxidation of formaldehyde on different modified electrodes has been considered as an advantageous technology for reducing its toxicity[3]. It is also of considerable interest for fuel cells due to the potentiality of formaldehyde as energy material[4]. This requires, however, that the electrode material should be a good catalyst for such anodic reaction and has a good anti- poisoning property against CO-type poisoning intermediates, which may occupy the active sites of the electrode and obstruct the oxidation reaction. According to the literature, noble metals such as Pt, Pd and Ag and their combinations[5,6]are the most effective catalysts for the oxidation of formaldehyde. Nevertheless, they are relatively scarce and therefore expensive, and they suffer

from deactivation caused by the adsorption of poisoning compo- nents on their surfaces. Recently, many studies were focused on the development of alternate low-cost non-noble metal catalysts.

Copper is a less noble metal but several studies have considered this metal as a good candidate for the design of new catalysts, especially because of its very remarkable electric conductivity, good stability and its low-cost[7–9].

Electroless copper deposition is a promising route to realize copper-based catalysts due to its relatively low-cost, simplicity, low processing temperature, good adherence and high physico- chemical properties of the deposits [10]. This work investigates the oxidation of formaldehyde on a copper-coated epoxy glass electrode prepared using electroless copper plating. The prepared electrode is relatively inexpensive and exhibits high electrocatalytic activity with good stability towards formaldehyde oxidation in alkaline solution.

2. Experimental details

Copper films were electroless deposited on epoxy glass (EG) substrate (12 cm²) as follows: first, the substrate was sonicated in 0.1 M NaOH for 5 min and rinsed with distilled water. After cleaning, the substrate was treated in 0.05 M SnCl2/0.5 M HCl solution for 5 min. This treatment aims to sensitize the substrate to the

⇑ Corresponding author at: Research Center in Industrial Technologies CRTI, P.O. Box 64, Cheraga 16014, Algiers, Algeria.

E-mail address:dcharif@hotmail.fr(C. Dehchar).

Materials Letters 228 (2018) 439–442

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Materials Letters

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