Electrooxidation behavior of ethanol toward carbon microbead-encapsulated ZnO particles derived from coffee waste

Zafar Khan Ghouri, Khaled Elsaid, Ahmed Abdel-Wahab, Ahmed Abdala, Mohammad Zahid Farhad

Research output: Contribution to journalArticle

Abstract

Carbon microbead-encapsulated ZnO (CM-ZnO) particles have been synthesized from the spent coffee ground (SCG) by chemical activation with ZnCl2 followed by calcination at 700 ℃ in N2 environment. Interestingly, ZnCl2 can act as an activating agent as well as a precursor for ZnO particles. The structure of the core and shell of the CM-ZnO was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Moreover, X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) studies confirmed the presence of the encapsulated ZnO particles. The Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) plots showed a well-developed porous structure with a specific surface area of 210 m2/g, average pore volume of 1.12 cm3/g, and an average pore radius of 31.7 Å. The electrooxidation behavior of ethanol toward the synthesized CM-ZnO was then studied using cyclic voltammetry (CV) technique. For comparison, two types of modified electrodes were prepared: the first one with the non-activated SCG and the second one with the CM-ZnO. The electrochemical measurements of the prepared CM-ZnO demonstrated higher electrocatalytic activity with a current density of ~ 35 mA/cm2 at 0.4 V vs. Ag/AgCl for ethanol electrooxidation in an alkaline medium. The electrochemical measurements specified that the presence of ZnO particles and the high surface area of the activated sample have a significant influence on electrooxidation activity. Therefore, the introduced CM-ZnO particles could be an alternative and effective non-precious electrocatalyst for ethanol electrooxidation.

Original languageEnglish
Pages (from-to)6530-6537
Number of pages8
JournalJournal of Materials Science: Materials in Electronics
Volume31
Issue number9
DOIs
Publication statusPublished - 1 May 2020

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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