La+3-doped CoFe2O4@MXene bifunctional electrocatalyst for superior OER and HER activity

Abstract

The lanthanum doped cobalt ferrite (La⁺³-CoFe₂O₄) incorporated in MXene sheets bifunctional electrocatalyst was prepared and then subjected to various analyses to assess their structural, morphological, and functional group characteristics. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) were employed for this purpose. The electrochemical performance of La-CoFe₂O₄@MXene was investigated in an alkaline solution to assess the bifunctional (OER/HER) performances. The results revealed that La-CoFe₂O₄@MXene exhibited significantly lower overpotential and a lesser Tafel slope during OER compared to both CoFe₂O₄ and La-CoFe₂O₄ materials. Similarly, during HER, La-CoFe₂O₄@MXene demonstrated superior performance. The electrochemical impedance (EIS) analysis was also conducted on all samples. These results indicated that the La-CoFe₂O₄@MXene electrocatalyst displayed reduced charge transfer resistance (2.18 Ω) and a higher exchange current density (2.94 mA cm⁻²) compared to its counterparts. These results collectively demonstrate the exceptional electrocatalytic behavior of La-CoFe₂O₄@MXene. This enhanced performance is likely attributable to the synergistic effect of lanthanum doping, which introduces defects into the material, and the presence of MXene sheets, which facilitates faster charge transfer within the electrocatalyst. To the best of our knowledge, this is the first study to explore La-CoFe₂O₄@MXene for water splitting. Our results demonstrate that this material requires significantly lower overpotential for OER and HER in an alkaline medium, showcasing its potential as an efficient and cost-effective catalyst for water splitting.

Graphical Abstract