Heterojunction interface editing in Co/NiCoP nanospheres by oxygen atoms decoration for synergistic accelerating hydrogen and oxygen evolution electrocatalysis

Controllable designing of well-defined heterojunction nanostructures provides an insightful strategy for accelerating the kinetics of the hydrogen and oxygen evolution reactions (HER/OER), but such task is still challenging. Herein, we proposed a protocol of heterojunction interface editing (HIE) strategy by oxygen atoms decoration for synergistic boosting electrocatalytic HER and OER performances. A novel Co/NiCoP nanospheres (NSs) heterojunction was synthesized by crystal seed template transformation method with Ni5P4 microspheres as seeds. The effective oxygen atoms interface editing increased the oxidation state of Co atoms and prolonged the Co-P bond length of Co/NiCoP NSs heterojunction, thus the electron localization on P sites was enhanced, leading to the dramatically elevated HER and OER performances simultaneously. The as-constructed O-Co/NiCoP NSs show excellent electrocatalytic activity with 361 and 430 mV vs. reversible hydrogen electrode (RHE) to arrive high current density of 300 mAcm−2 for HER and OER in 1 M KOH as well as good stability. The proposed HIE concept could provide a new perspective on the catalyst design for energy conversion systems.