Rapid Surface Reconstruction of Te-Doped NiFe Layered Double Hydroxide for Robust Oxygen Evolution at High Current Density

Abstract

Surface reconstruction generates genuine active phases under an electrochemical oxygen evolution reaction (OER); however, most OER catalysts exhibit slow self-reconstruction due to their relative stability in electrochemistry. Therefore, it is highly essential to rationally design precatalysts capable of rapidly generating more active OER species. Herein, a novel reconfigurable Tedoped NiFe layered double hydroxide (Te-NiFe LDH/NF) precatalyst is prepared, which exhibits ultrafast and in-depth selfreconstruction, significantly enhancing the activity for the OER step. By employing various in/ex situ techniques and theoretical calculations, the distinctive structure of Te-NiFe LDH/NF along with the alkaline electrolyte are identified as pivotal factors for facilitating the phase transition. The presence of Te cations can effectively reduce the energy barrier, thereby providing the feasibility of continuous reconstruction, while the alkaline electrolyte supplies a complement of OH − to form highly active oxyhydroxides. Besides, Te is doped in situ into the NiFeO x H y lattice (Te-NiFeO x H y /NF), leading to optimized binding energies of the OER intermediates and reduced energy barriers for the rate-determining step (RDS), ultimately enhancing the OER performance. As such, the self-restructured Te-NiFeO x H y /NF only required 208 and 310 mV to achieve 10 and 500 mA cm −2 , respectively, together with high current stability for 300 h. This study provides a rational design strategy to develop highly efficient electrocatalysts for the OER through surface reconstruction.