Zn-substituted MnCo2O4 nanostructure anchored over rGO for boosting the electrocatalytic performance towards methanol oxidation and oxygen evolution reaction (OER)

A. Rebekah, Sengeni Anantharaj, C. Viswanthan, N. Ponpandian

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

Mixed valence spinel oxides have emerged as an attractive and inexpensive anode electrocatalyst for water oxidation to replace noble metals based electrocatalysts. The present work demonstrates the facile synthesis of Zn substituted MnCo2O4 supported on 3D graphene prepared by simple hydrothermal technique and its application as an electrocatalyst for water oxidation and methanol oxidation. The physico-chemical properties of the nanocatalyst were studied using various microscopic, spectroscopic and diffraction analyses confirming the formation of the composite. The electrocatalytic performance of the prepared electrocatalyst was evaluated using potentiodynamic, potentiostatic and impedance techniques. The synthesized Zn1-xMnxCo2O4/rGO electrocatalyst with x = 0.2 and 0.4 offered the same onset potential and overpotential at 10 mA/cm2. However, catalyst x = 0.4 delivered a higher current density indicating the superiority of the same over other compositions which is attributed to better kinetics that it possessed for OER as revealed by the smallest Tafel slope (80.6 mV dec−1). The prepared electrocatalysts were tested for methanol oxidation in which electrocatalyst Zn1-xMnxCo2O4/rGO with x = 0.4 shows a better electrochemical performance in oxidizing methanol with the higher current density of 142.3 mA/cm2. The above catalyst also revealed excellent stability and durability during both MOR and OER, suggesting that it can be utilized in practical applications.

Original languageEnglish
Pages (from-to)14713-14727
Number of pages15
JournalInternational Journal of Hydrogen Energy
Volume45
Issue number29
DOIs
Publication statusPublished - 2020 May 26

Keywords

  • Electrocatalyst
  • Methanol oxidation reaction
  • Nanostructures
  • Oxygen evolution reaction
  • Spinel oxides
  • rGO

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology

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