Eu-doped BaTiO3 perovskite as an efficient electrocatalyst for oxygen evolution reaction

Abstract

The development of a noble metal-free catalyst for oxygen evolution reaction (OER) is crucial to enable efficient oxygen production at a low price and global scale. Herein, we have reported the synthesis of Eu-doped barium titanate (Eu-BaTiO3) at various concentrations of europium ranging from 1 to 5mol% via solid-state reaction method. The synthesized samples were characterized by various techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and cyclic-voltammetry to study structural, morphological, elemental and electrocatalytic behavior of undoped and doped samples. XRD confirmed the pure phase formation of Eu-doped BaTiO3. The morphological results exhibited the hexagonal morphology of synthesized nanoparticles. The elemental mapping of the sample shows that the europium (Eu) is uniformly distributed over the surface of the sample. The effect of the europium concentration on the electrocatalytic activity of BaTiO3 has been studied in detail. The as-prepared sample shows remarkable electrochemical performance towards OER in 1 ​M KOH solution. The sample exhibited a low Tafel slope of 138.34 mV/dec and achieved a low overpotential of 1.60 ​V at a current density of 10 ​mA/cm2. Moreover, synthesized samples performed excellent stability over 2000 cyclic voltammetry (CV) cycles. The present study provides a new pathway towards the development of inexpensive and highly efficient rare-earth doped electrocatalysts.