A Trimodal Porous Cobalt‐Based Electrocatalyst for Enhanced Oxygen Evolution

Abstract Constructing porous electrodes with proper surface structures and mass‐transport channels is crucial for their high performance electrocatalytic applications such as oxygen evolution reaction (OER). Here a cobalt (Co)‐based hierarchical porous material (HP‐Co), which is realized through a scalable phase‐separation approach, is reported. Taking the advantage of a unique trimodal structure with macropores, mesopores, and micropores, the HP‐Co electrocatalysts exhibit better OER performance than general Co‐based nanoporous electrocatalysts due to more effective use of active sites. Meanwhile, this phase‐separation approach can be extended to prepare various hierarchically nanoporous electrocatalysts via facile doping with heteroatoms including Fe and Ni, to fine‐tune their surface properties and intrinsic activities.