in situ Tracking Water Oxidation Generated Lattice Strain Effects in Layered Double Hydroxides Nanosheets

Abstract

AbstractLayered double hydroxides (LDHs) have been identified as a potential catalyst for water oxidation, and it is recognized that they exhibit a dynamic and heterogeneous evolution of their lattice structure during their operation. In this study, we investigate the dynamic and heterogeneous evolution of LDHs during operation as a water oxidation catalyst usingin situelectrochemical atomic force microscopy. Our results demonstrate that the lattice strain in LDHs triggers its heterogeneous structural dynamics at the nanoscale and has implications for the oxygen evolution reaction (OER) performance. The NiCo LDHs transforms to catalytically active NiCoOx(OH)2−xphase during operation, which produces compressive lattice strain and reversible tensile strain. The compressive strain along active edge sites of the nanosheets results in structural collapse and long-term degradation. Additionally, nanobubbles nucleate and grow at the electrocatalytic interfaces, leading to surface blockage and deterioration of catalytic efficiency. By engineering defects, we can precisely tune the strain and gas behavior during operation, leading to improved OER activity and stability among LDHs-based catalysts