Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting

Abstract

The aim of the conducted research was to develop hybrid nanostructures formed from MnCo₂O₄ and exfoliated graphite. Carbon added during the synthesis allowed for obtaining a well-distributed MnCo₂O₄ particle size with exposed active sites contributing to the increased electric conductivity. The influence of the weight ratios of carbon to a catalyst for hydrogen and oxygen evolution reactions was investigated. The new bifunctional catalysts for water splitting were tested in an alkaline medium with excellent electrochemical performance and very good working stability. The results for hybrid samples show better electrochemical performance compared to the pure MnCo₂O₄. The highest electrocatalytic activity was for sample MnCo₂O₄/EG (2/1), where the value of the overpotential was 1.66 V at 10 mA cm⁻², and also for this sample a low value of Tafel slope (63 mV dec⁻¹) was denoted.