V-Integration Modulates t_2g-Electrons of a Single Crystal Ir_1-x(Ir_0.8V_0.2O ₂)_x-BHC for Boosted and Durable OER in Acidic Electrolyte

Realizing efficacious p-donation from the O 2p orbital to electron-deficient metal (t(2g)) 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 p-donation and the adsorption ability for *O and *OOH, herein, a facile strategy to modulate the electron transfer from electron-rich t(2g)-orbitals to electron-deficient t(2g)-orbitals, via strong p-donation from the p-symmetry lone pairs of the bridging O2-, and the d-band center of a biomimetic honeycomb (BHC)-like nanoarchitecture (Ir-1-(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 Ir-1-(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 p-symmetry (t(2g)) d-orbitals and the band structure, to achieve excellent activity and durability in acidic environment.