Sonication strategy for anchoring single metal atom oxides (W, Cu, Co) on CeO₂-rGO for boosting electrocatalytic...

In the field of electrocatalysis, single-atomic-layer tungsten, copper, and cobalt oxide on CeO₂, ethylene diamine (ED) and reduced graphene oxide (rGO) supported materials shows tremendous potential. Despite the enormous interest in single metal atom oxide (SMAO) catalysts, it is still very difficult to directly convert readily available bulk metal oxide into single atom oxide. It is crucial and tough to create high performance materials for the oxygen evolution reaction (OER) in an alkaline environment. Herein, a single tungsten, copper and cobalt atom oxide (SMAO) anchored on the CeO₂ atomic layer and overall components deposited on the rGO (rGO-ED-CeO₂-WCuCo) is prepared through a one-pot sonication technique. The presence of SMAO is identified by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging. The electrocatalytic performance of final rGO-ED-CeO₂-WCuCo-30 nanocomposite for the OER in 1 M KOH electrolyte is evidenced by providing low overpotential of 283 mV at 10 mA cm^-2. The Tafel slope for OER using rGO-ED-CeO₂-WCuCo-30 electrocatalysts is 57.03 mV dec^-1. The electrocatalytic activity of rGO-ED-CeO₂-WCuCo-30 nanocomposites for OER was noticeably increased when compared to bare CeO₂ nanorods (401 mV), rGO-ED-CeO₂-WCo-30 (345 mV), rGO-ED-CeO₂-WCu-30 (340 mV) and rGO-ED-CeO₂-WCuCo-20 (321 mV) samples.