Single W, Cu, Co atom oxide embedded in Co3O4-rGO for boosting electrocatalytic oxygen evolution reaction and for photodegradation of tetracycline

Abstract

One of the most important phenomena in developing renewable and sustainable energy methods is electrocatalytic water splitting. Higher loadings of single metal atom oxide (SMAO) (M: W, Cu, and Co) in Co3O4-rGO catalysts are credited with boosting their efficiency in electrocatalytic oxygen evolution reaction (OER) and photodegradation of tetracycline (TC). In this work, we investigated the catalytic activity of electrocatalysts for OER by preparing ultrathin Co3O4 nanosheets and reduced graphene oxide (rGO) embedded with SMAO (rGO-ED-Co3O4-WCuCo-30) using a simple one-pot sonication process. The well-designed rGO-ED-Co3O4-WCuCo-30 electrocatalyst allows for the delivery of current densities of 10 and 100 mA cm−2 at overpotentials of 291 and 365 mV, respectively, with a relatively modest Tafel slope of 57.9 mV dec−1 during OER. The densely embedded SMAO particles on the Co3O4 surface are responsible for this behavior because they increase the electrochemical surface area with a large number of active sites in a synergistic manner. The rGO-ED-Co3O4-WCuCo-30 catalyst was used effectively in OER with outstanding long-term stability for more than 24 h. The photocatalytic results further show that the activity of Co3O4 was significantly enhanced by the addition of SMAO, with the TC degradation efficiency of 97.57%.