Engineering a Built-in Electric Field in a Wood-Derived Ni Fe Co-LDH @NiFe Heterojunction for Enhanced Bifunctional Water Splitting

Abstract

Optimizing the electronic structure is pivotal augmenting the intrinsic catalyst activity. The fabrication of a rationally designed heterostructure is an effective approach to modulate the electronic landscape. Regarding this issue, we constructed the self-supported metal/wood-based electrocatalysts featuring a three-dimensional, layered and porous architecture. By utilizing NiFe alloy nanospheres as a bridging component to interconnect with NiFeCo-LDH, we have established a robust heterojunction that is securely anchored onto a wood-derived substrate. Wood's natural 3D porous structure promotes active site exposure and gas release, while its hydrophilicity and the integration of NiFe alloy with NiFeCo-LDH enhance electrolyte transport and electron transfer, boosting the substrate's catalytic activity. This innovative construct leverages the synergistic effects at the metal-organic heterointerface, thereby enhancing electron transfer kinetics and catalytic efficiency in electrochemical applications. The synthesized NiFeCo-LDH@NiFe/CW catalyst, with its enhanced surface electron density, shows reduced oxygen intermediate adsorption energy and excellent bi-functional electrocatalytic performance with low overpotential (90 mV for OER and 70 mV for HER) and long-term stability over 24 hours. This work provides a new way for high value utilization of wood materials.