Development and evaluation of cost-effective and green Bi-functional nickel oxide decorated graphene electrocatalysts for alkaline fuel cells

Abstract

Fuel cells (FCs) are one of the most promising forms of energy production. The huge challenge of fuel cell devices is the development of bi-functional, non-precious and highly active catalysts. In this study, nickel oxide supported on graphene (NiO/G) was synthesized by one pot thermal decomposition process of mineral water waste bottles with nickel oxide. Under alkaline conditions, the composite was employed as an electrode catalyst, replacing platinum (Pt) as a catalyst for the oxygen reduction reaction (ORR). The electrochemical behavior of synthesized materials exhibited an increase in oxygen reduction reaction using NiO/G with respect to using graphene only as a catalyst. All steps of the reaction at the efficient four-electron reduction path were spontaneous. The half-wave potential (E1/2) of the (ORR) equals −0.1 V and −0.18 V for NiO/G and graphene, respectively. The oxygen evaluation reaction (OER) was also investigated. The results showed that the OER current and the current density of NiO/G were significantly higher than those of graphene, which revealed the best OER performance among the graphene samples. Using the NiO/G composite in FCs is anticipated to lower the cost and boost the use of electrochemical energy devices, and it could be advantageous in other catalytic systems.

Keywords

• Bi-functional electrocatalyst
• Nickel oxide
• Oxygen reduction reaction
• Alkaline fuel cell