Insight into the Facilitated surface reconstruction of NiFe layered double hydroxide by constructing heterostructures with Prussian blue analogues for enhanced oxygen evolution reaction

The dynamic surface electrochemical reconstruction of electrocatalysts in alkaline media for oxygen evolution reaction (OER) has been extensively documented, especially for layered double hydroxides (LDHs). However, there remines a limited understanding on how to effectively promote electrochemical reconstruction towards the desired highly active oxyhydroxide surface,which is crucial for enhancing the OER performance. The NiCo-PBA/NiFe LDH heterostructured catalyst was successfully synthesized by a one-step hydrothermal method. The incorporation of Prussian blue analogues (PBAs) was found to significantly promote the surface depth reconstruction of NiFe LDH, achieving a much higher degree of reconstruction compared to the natural electrochemical activation. In-situ Raman spectroscopy, various ex-situ characterizations, and density functional theory (DFT) calculations reveal that the introduction of PBAs intensifies the dissolution-reconstruction process and facilitates phase transition to form high-valent oxyhydroxide structures with optimized electron transfer pathways. The reconstructed NiCo-PBA/NiFe LDH-Re100 demonstrates exceptional electrocatalytic activity and long-term durability during the OER process. This study provides novel insights into the design of heterostructured catalysts and highlights their significant potential for applications in efficient electrocatalysis.