The Tunability of Oxygen Evolution Reaction in Flexible Van der Waals Manganite Membrane

Abstract

Transition metal oxides (TMOs) have been intensively investigated in varied electrochemical processes owing to their features of low cost, stability, and substantial activity, etc. The strain engineering of a TMO has been proposed as a promising method for enhanced electrochemical activities due to its strongly electron correlated nature. Generally this type of investigation is carried out by separated TMO thin films on various substrates with a different lattice constant. In this study, the oxygen evolution reaction (OER) activity of Van der Waals La2/3Sr1/3MnO3 (LSMO) membrane is studied as a function of continuous strain manipulation via curvature change. It is found that a total of ≈800% OER activity tunability can be achieved by only ≈0.4% in situ strain modulation. Then the variation of in‐plane interaction strength of the eg orbital is found to correspond to the sensitive OER tunability and 3dx2−y2 orbital occupancy is favored in an OER enhancement of LSMO.

The tunability of oxygen evolution reaction performance in La0.67Sr0.33CoO3 van der Waals membrane

“…The thickness of the mica obtained films was 40 nm. After sputtering, the film was naturally cooled to room temperature under a pressure of 26.7 Pa. 15 The thickness of the exfoliated single-layer mica sheet was tested by a scanning electron microscope (SEM). The surface morphology of the mica before and after the LSCO film was measured by applying an atomic force microscope (AFM), and the structure of the film was analyzed using X-ray diffraction (XRD).…”

Cobalt-Based Perovskite Electrodes for Solid Oxide Electrolysis Cells

“…Flua's group further proved that the decomposition of LNO on GDC was induced by element diffusion at the LNO-GDC interphase [19]. This decomposition phenomenon was also found at the La 0.5 Sr 0.5 MnO 3 (LSMO) electrode [20]. The LSMO gradually cracked into nanoparticles due to oxygen ions migrating through the electrolyte during anodic polarization, which led to an alteration in valence of manganese ions and thereafter resulted in lattice shrinkage and consequent breakdown into particles [21,22].…”

Strain Modified Oxygen Evolution Reaction Performance in Epitaxial, Freestanding, and Van Der Waals Manganite Thin Films

“…The simulated diagrams of the d band center are shifted via strain effect and the oxygen vacancies lead to band gap change are presented in Figure a. The chemisorption strength is closely related to the d band center position. ,,− Tensile strain gives rise to the decreased overlap of metal d orbitals and narrows the energy bandwidth which lifts the d band center position and lowers the bandwidth, thus pushing less antibonding states nether Fermi energy and reinforcing the binding energy of adsorbates. − ,− However, the high coordination numbers would expand metal energy bands leading to downward shifting of the d band center and weakened adsorption ability with OH – . Thereby, the OER activity of flexible LSMO with only tensile strain is enhanced due to the d band center change.…”