Exploring new materials is essential in the field of material science. Especially, searching for optimal materials with utmost atomic utilization, ideal activities and desirable stability for catalytic applications requires smart design of materials’ structures. Herein, we report iridium metallene oxide: 1 T phase-iridium dioxide (IrO 2 ) by a synthetic strategy combining mechanochemistry and thermal treatment in a strong alkaline medium. This material demonstrates high activity for oxygen evolution reaction with a low overpotential of 197 millivolt in acidic electrolyte at 10 milliamperes per geometric square centimeter (mA cm geo −2 ). Together, it achieves high turnover frequencies of 4.2 s UPD −1 (3.0 s BET −1 ) at 1.50 V vs. reversible hydrogen electrode. Furthermore, 1T-IrO 2 also shows little degradation after 126 hours chronopotentiometry measurement under the high current density of 250 mA cm geo −2 in proton exchange membrane device. Theoretical calculations reveal that the active site of Ir in 1T-IrO 2 provides an optimal free energy uphill in *OH formation, leading to the enhanced performance. The discovery of this 1T-metallene oxide material will provide new opportunities for catalysis and other applications.
Dan-Ni Li,An-hui Zhou,Xiang Shao,Lin Zhu,Yan Du,Li-Mei Cao,Cheng-Long Ma,Ji Yang
Recently, surface reconstruction derived from Ir-based derivatives could achieve satisfactory oxygen evolution performance. Herein, ultra-long nanowire hollandite structured Rb 0.17 IrO 2 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 Rb 0.17 IrO 2 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.
危险品化学品经营许可证（带存储）