V‐Integration Modulates t2g‐Electrons of a Single Crystal Ir1‐x(Ir0.8V0.2O2)x‐BHC for Boosted and Durable OER in Acidic Electrolyte

Abstract

AbstractRealizing efficacious π‐donation from the O 2p orbital to electron‐deficient metal (t2g) d‐orbitals along with separately tuned adsorption of *O and *OOH, is an imperious pre‐requisite for an electrocatalyst design to demonstrate boosted oxygen evolution reaction (OER) performance. To regulate the π‐donation and the adsorption ability for *O and *OOH, herein, a facile strategy to modulate the electron transfer from electron‐rich t2g‐orbitals to electron‐deficient t2g‐orbitals, via strong π‐donation from the π‐symmetry lone pairs of the bridging O2−, and the d‐band center of a biomimetic honeycomb (BHC)‐like nanoarchitecture (Ir1‐x(Ir0.8V0.2O2)x‐BHC) is introduced. The suitable integration of V heteroatoms in the single crystal system of IrO2 decreases the electron density on the neighboring Ir sites, and causes an upshift in the d‐band center of Ir1‐x(Ir0.8V0.2O2)x‐BHC, weakening the adsorption of *O while strengthening that of *OOH, lowers the energy barrier for OER. Therefore, BHC design demonstrates excellent OER performance (shows a small overpotential of 238 mV at 10 mA cm−2 and a Tafel slope of 39.87 mV dec−1) with remarkable stability (130 h) in corrosive acidic electrolyte. This work opens a new corridor to design robust biomimetic nanoarchitectures of modulated π‐symmetry (t2g) d‐orbitals and the band structure, to achieve excellent activity and durability in acidic environment.