Directed Mass and Electron Transfer Promoted by Hierarchical Porous Co–P–O Leads to Enhancement of the Overall Water Splitting Efficiency

Optimization of the efficiencies of both macroscale mass transport and microscale electron transfer is highly desired for achieving high-performance electrocatalysts but still remains a great challenge. Herein, a facile topological conversion method is developed to synthesize a novel O-incorporated CoP derivative (denoted as Co–P–O) with directed mass and electron transfer effects, which benefits from its hierarchical porous structure and internal atomic n-p homojunction, respectively. As a result, Co–P–O achieves optimal hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance with low overpotentials (113 and 256 mV at 10 mA cm^–2, respectively) and enhanced durability in water splitting. Density functional theory calculations further reveal that both the degree of polarization/rearrangement of the overall surface charge and the delocalization effects of the d electrons of Co–P–O are enhanced, leading to optimal adsorption of H₂O/OH^– and desorption of the generated gases for enhancing HER and OER activities.