Interface oxidation induced amorphous/crystalline 1D hollandite Rb0.17IrO2 for efficient oxygen evolution reaction

Abstract

Recently, surface reconstruction derived from Ir-based derivatives could achieve satisfactory oxygen evolution performance. Herein, ultra-long nanowire hollandite structured Rb0.17IrO2 was synthesized and a nano-amorphous layer with a thickness of ∼1.5 nm was achieved by interfacial oxidation treatment. The prepared catalyst exhibits outstanding water oxidation activity with an oxygen evolution reaction (OER) current density of 10 mA cm−2 at 330 mV for robust continuous operation in acidic media. Through the spectroscopic and density functional theory (DFT) theoretical calculations, we demonstrate that the nano-amorphous layers induced by interfacial oxidation on the one-dimensional (1D)-nanowire surface have enhanced O-2p centers and increased Ir-O hybridization compared to the bulk Rb0.17IrO2 phase, which essentially balances the adsorption energy of the intermediates. Effectively incorporating surface reconstruction behavior could significantly improve catalyst activity. This work effectively combines 1D Ir-based materials and surface reconstruction, which provides a strategy for the subsequent full utilization of Ir-based materials applied on OER process.