The Effects of Compositional Tuning on the Bifunctional Oxygen Electrocatalytic Behavior of Nickel Sulfoselenides

Nickel sulfoselenides (NiSSe) are a family of electrocatalysts with promise for application to the oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and therefore bifunctional oxygen electrocatalysis (BOE). Tuning the S/Se composition of a series of Ni3S2–xSex NiSSe influences electrocatalytic performance, with a near unity S/Se ratio optimal for OER and Se-rich compositions optimal for ORR and BOE applications. Using chemical and physical characterization, we show that Se addition results in a greater oxidative stability and electrocatalytic performance. Finally, we demonstrate NiSSe electrocatalysts as BOEs in Zn–air batteries and find that they are more stable than commercial Pt/C electrocatalysts.