A moss-like CoB/CeO2 heterojunction as an efficient electrocatalyst for the oxygen evolution reaction under alkaline conditions†

Heterostructure construction has become increasingly recognized as an effective strategy to enhance oxygen evolution reaction (OER) performance due to the exposed active surfaces and improved mass/charge transfer. Inspired by natural plant structures, this study develops a unique moss-like amorphous/crystalline (CoB/CeO₂) heterojunction. This distinctive moss-like morphology facilitates the formation of staggered sheet structures in the catalyst, providing more active sites and open channels for reaction intermediates and gas release. Benefiting from the hydrophilic properties offered by the moss-like morphology, CoB/CeO₂ exhibits excellent OER catalytic performance in 1 M KOH, requiring only 247 mV at 100 mA cm⁻². Physicochemical characterization and mechanistic studies reveal that the close nanoscale features between CoB and CeO₂ create abundant binary interfaces, optimize the electronic configuration, induce changes in electronic states, and provide abundant defect sites, thereby enhancing charge transfer capabilities. This work presents a new paradigm for the design of efficient and durable OER electrocatalysts.