Bioinspired "Soil-Tree" Multiscale Engineered F-NiFeAl-LDH/MXene Heterostructures for Robust Photoelectrocatalytic...

Developing photoelectrochemical synergistic catalysts for the oxygen evolution reaction (OER) that combine high activity and long-term stability is crucial for industrial hydrogen production, but simultaneously optimizing site utilization and bubble desorption kinetics remains extremely challenging. Inspired by the biomimetic logic of "soil-tree," this paper successfully developed a multi-scale synergistically enhanced F-NFA-LDH/MX photoelectrocatalyst by in situ constructing a vertical F-NiFeAl-LDH nanosheet array on a monolayer MXene conductive substrate and supplementing it with low-temperature gas-phase fluorination. In this system, MXene acts as a conductive "soil," constructing a continuous electron transport network that significantly reduces interfacial impedance; the vertical array, acting as a "tree," forms an open 3D mass transport channel, maximizing the active area while accelerating bubble desorption through excellent exhaust kinetics, ensuring the robustness of the system. At the atomic scale, fluorination modification reshapes the electronic structure of the metal center, inducing a high-valence electron-deficient environment and abundant oxygen vacancies, significantly enhancing intrinsic catalytic activity. Experimental results show that the F-NFA-LDH/MX exhibits an overpotential of only 204 mV at 10 mA cm^-2 under illumination and operates stably for over 100 h at 20 mA cm^-2. Furthermore, its unique architecture endows the system with superior light-harvesting capabilities and photoelectric synergy. This research, through comprehensive design from atomic-level electronic manipulation to macroscopic dynamics, provides a practical strategy for developing highly efficient energy conversion catalysts.