Sol-gel synthesis of Ce0.8Sr0.2Co1-(x+y)NixFeyO3-δ (x = 0.1, 0.2, and y = 0.2, 0.5, 0.7)—a nanocomposite-type electrocatalyst for the oxygen evolution reaction in alkaline media

Abstract

We report on nanocomposite materials that are both active and stable for the oxygen evolution reaction (OER) in alkaline media. Ce0.8Sr0.2Co0.6Ni0.2Fe0.2O3-δ (CSCNF1), Ce0.8Sr0.2Co0.3Ni0.2Fe0.5O3-δ (CSCNF2), and Ce0.8Sr0.2Co0.2Ni0.1Fe0.7O3-δ (CSCNF3) that contain a lanthanide, in the form of Cerium (Ce) in the A site and varied compositions of Co, Ni, and Fe in the B site, were synthesized by a typical sol-gel route and compared with a benchmark nanocomposite, i.e. Ba0.5Sr0.5Co0.8F0.2O3-δ, synthesized by the same method. The crystal structure was examined employing X-ray diffraction (XRD) and the textural properties were examined using Fourier transform infrared spectroscopy (FTIR). The morphology and microstructure were examined employing scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The CSCNF1 (n = 1, 2, or 3) nanocomposite materials exhibited high intrinsic activities, by displaying overpotentials of 0.290 V, 0.470 V, and 0.350 V for CSCNF1, CSCNF2, and CSCNF3, respectively, at 10 mA cm−2, and Tafel slopes of 54.1 mV dec−1, 71.3 mV dec−1, and 62.8 mV dec−1, respectively. CSCNFn (n = 1-3) nanocomposites compared with BSCF nanocomposite established its viability as a good electrocatalyst. They exhibited good electrocatalytic performance and stability and deserve further investigation as electrocatalysts for the OER in alkaline solution