High-performance oxygen evolution reaction activity at low and higher current densities using nanostructured CeO2 and Plasma-assisted Bi@CeO2 electrocatalysts

Abstract

Herein, pristine nanostructured cerium oxide (CeO2) electrode (HC) was fabricated via an alkali-free hydrothermal, exhibiting high OER behaviors at low current density. The HC electrode displayed a low overpotential of 0.32 V, low Tafel slope of 61.6 mV dec-1, and high stability of 99.6 % for 15 h at a current density of 10 mA cm−2. To accelerate the kinetic of OER at high current density, a binary Bi@CeO2 plasma-activated electrode (PBC) was prepared as an effective electrocatalyst to evolve larger oxygen gas. The PBC electrode exhibited a low overpotential (0.42 V and 0.46 V) at higher current densities of 50 mA cm−2 and 250 mA cm−2, a small Tafel slope of 47.4 mV dec-1, and excellent stability of 99 % for 15 h at a current density of 100 mA cm−2. The results suggested that CeO2 and its composite Bi@CeO2 are promising potential active OER electrocatalysts.