Fe3O4@MoS2/RGO as an effective nano-electrocatalyst toward electrochemical hydrogen evolution reaction and methanol oxidation in two settings for fuel cell application

Mohammad Bagher Askari; Amirkhosro Beheshti-Marnani; Majid Seifi; Seyed Mohammad Rozati; Parisa Salarizadeh

doi:10.1016/j.jcis.2018.11.019

Fe₃O₄@MoS₂/RGO as an effective nano-electrocatalyst toward electrochemical hydrogen evolution reaction and methanol oxidation in two settings for fuel cell application

J Colloid Interface Sci. 2019 Mar 1:537:186-196. doi: 10.1016/j.jcis.2018.11.019. Epub 2018 Nov 8.

Authors

Mohammad Bagher Askari¹, Amirkhosro Beheshti-Marnani², Majid Seifi³, Seyed Mohammad Rozati⁴, Parisa Salarizadeh⁵

Affiliations

¹ Department of Physics, Faculty of Science, University of Guilan, P.O. Box 41335-1914, Rasht, Iran; Department of Physics, Payame Noor University (PNU), P.O.Box:19395-3697, Tehran, Iran. Electronic address: mbaskari@phd.guilan.ac.ir.
² Department of Chemistry, Payame Noor University (PNU), P.O. Box 19395-4697, Tehran, Iran. Electronic address: Beheshti@pnu.ac.ir.
³ Department of Physics, Faculty of Science, University of Guilan, P.O. Box 41335-1914, Rasht, Iran. Electronic address: seifi@guilan.ac.ir.
⁴ Department of Physics, Faculty of Science, University of Guilan, P.O. Box 41335-1914, Rasht, Iran. Electronic address: smrozati@guilan.ac.ir.
⁵ High-Temperature Fuel Cell Department, Vali-e-Asr University of Rafsanjan, Rafsanjan 1599637111, Iran. Electronic address: p.salarizadeh@vru.ac.ir.

PMID: 30445348
DOI: 10.1016/j.jcis.2018.11.019

Abstract

A three-component nano-electrocatalyst, magnetite coated molybdenum disulfide hybridized with reduced graphene oxide (Fe₃O₄@MoS₂/RGO), is synthesized by a two-step hydrothermal method. This catalyst is applied as an effective substitution for the platinum catalyst in methanol oxidation and hydrogen evolution reactions. Cyclic voltammetry, chronoamperometry, and linear sweep voltammetry are used to evaluate the performance of the electrocatalyst in acidic and basic media. The results of methanol oxidation reaction on the hybridized nano-electrocatalyst showed good electrocatalytic properties with considerable diffusion currents. This fact is confirmed by the Tafel plots and the calculated kinetic parameters of electron transfer. Fe₃O₄@MoS₂/RGO showed an anodic transfer coefficient and exchange current of 0.464 and 4.80 × 10^-8, respectively that are higher than Fe₃O₄/RGO. The presence of the porous MoS₂ in catalyst has a key effect on supplying electroactive sites for electron transfer. Also, the high actual surface area obtained for the hybridized nano-electrocatalyst (A = 0.0295 cm²). The maximum power density of 35.03 mW cm^-2 obtained for a single cell containing the prepared hybridized catalyst as the anode which shows a competitive feature of the synthetic catalyst compared to other reports. Furthermore, the synthetic catalyst shows the low-value overpotential of 108 mV and Tafel slope of 48 mV dec^-1 during the hydrogen evolution process in acidic media. This is attributed to the synergistic effect between Fe₃O₄ and MoS₂ and also increase the electron transfer rate due to adding conductive RGO to the catalyst. The results show that the synthetic nanocatalyst can have promising applications for hydrogen evolution and methanol oxidation reactions.

Keywords: Direct methanol fuel cell; Hydrogen evolution reaction; Iron oxide; Molybdenum disulfide; Reduced graphene oxide.