Electrocatalytic activity of cerium oxide and a composite of cerium oxide with polyaniline (CeO2@PANI) for oxygen evolution reaction (OER)

Abstract

Electrochemical water splitting is an effective strategy that can be utilized to obtain energy from sustainable sources. Still, the substantial overpotential necessary for sluggish OER (oxygen evolution reaction) hinders extensive application. Herein, we synthesized CeO₂@PANI hybrid as an electrocatalyst for OER via the hydrothermal procedure. The synthesized electrocatalyst exhibited superior OER efficacy than pure CeO₂. The CeO₂@PANI hybrid was thoroughly studied using several analytical techniques including SEM (scanning electron microscopy), TGA (thermogravimetric analysis), BET (Brunauer–Emmett–Teller) and XRD (X-ray diffraction). These studies show that hybrid material has good crystallinity, particle like morphology and cubic framework, with a significant surface area. The electrocatalytic efficacy of the CeO₂@PANI hybrid was assessed in a basic solution (1.00 M KOH), demonstrating a reduced overpotential (η) of 226 mV, a Tafel value (36 mV/dec) at a current density (j) of 10 mA/cm² and a minimal charge transfer resistance (R_ct) of 0.8 Ω. The composite also displayed 30 hours of durability as evaluated by CA (chronoamperometry). The produced hybrid’s high catalytic efficiency can be associated with CeO₂ dispersed on the surface of PANI, which enhances electronic conduction. The hybrid of CeO₂ and PANI outcomes in higher surface area, more active regions, less resistivity along with exceptional durability that contribute to the increased efficiency for OER procedure.

Graphical Abstract