Interfacial P-O covalent bonds regulated electronic configuration in black phosphorus for improving oxygen evolution activity

Black phosphorus (P(black)) shows impressive physicochemical features for electrocatalysis including adjustable bandgap and high charge carrier mobility. However, the existence of solitary electron pairs in exfoliated P(black) nanosheets (EP(black)) leads to rapid surface degradation, resulting in unfavorable durability. Herein, a P-O bridge was created in the heterostructure EP(black)/vanadium-doped cobalt hydroxide with oxygen vacancy (EP (black)/V-CoO2-xH2) to stabilize and expedite oxygen evolution reaction (OER) activity. By bonding the solitary electron pairs of EP(black) and oxygen species (OH*) of V-CoO2-xH2, the distinctive P-O bridge resulted in important ligand effects that improved not merely the stability of EP(black) but effectively regulated the electron configuration of V-CoO2-xH2. DFT simulations revealed that directional interfacial electron migration from V-CoO2-xH2 to EP(black) facilitated the formation of pivotal OER intermediates and hence boosted OER activities. This study proposes a novel strategy to enhance the electrochemical properties of EP(black), which could be extended to a wide range of high-performance electrocatalyst systems.