In Situ Modulation of Oxygen Vacancies on 2D Metal Hydroxide Organic Frameworks for High‐Efficiency Oxygen Evolution Reaction

Abstract

The discovery of non‐precious catalysts for replacing the precious metal of ruthenium in the oxygen evolution reaction (OER) represents a key step in reducing the cost of green hydrogen production. The 2D d‐MHOFs, a new 2D materials with controllable oxygen vacancies formed by controlling the degree of coordination bridging between metal hydroxyl oxide and BDC ligands are synthesized at room temperature, exhibit excellent OER properties with low overpotentials of 207 mV at 10 mA cm−2. High‐resolution transmission electron microscopy images and density functional theory calculations demonstrate that the introduction of oxygen vacancy sites leads to a lattice distortion and charge redistribution in the catalysts, enhancing the OER activity of 2D d‐MHOFs comprehensively. Synchrotron radiation and in situ Raman/Fourier transform infrared spectroscopy indicate that part of oxygen defect sites on the surface of 2D d‐MHOFs are prone to transition to highly active metal hydroxyl oxides during the OER process. This work provides a mild strategy for scalable preparation of 2D d‐MHOFs nanosheets with controllable oxygen defects, reveals the relationship between oxygen vacancies and OER performance, and offers a profound insight into the basic process of structural transformation in the OER process.

NiFeLDH/Mo4/3B2−xTz/NF composite electrodes to enhance oxygen evolution performance

“…Xing et al 23 achieved improved OER performance by constructing a CoFeLDH@MnCoC heterojunction with an overpotential of 250 mV at a current density of 10 mA cm −2 . Shen et al 24 adopted an in situ modulation of oxygen vacancies on 2D metal hydroxide organic frameworks for a high-efficiency OER with a low overpotential of 207 mV at 10 mA cm −2 . Ashraf et al 25 synthesized a layered Ti 3 C 2 T z /V 2 O 5 (T z = F, Cl, or OH) catalyst for electrocatalytic water-splitting and discovered that the overpotentials of the HER and OER were 90 and 240 mV at 10 mA cm −2 , respectively.…”