Delaminated Mo2CTx MXene-coupled NiCo-LDH nanosheets as efficient non-precious metal anodes for anion exchange membrane water electrolysis

초록

Hydroxide-based layered double hydroxides (LDHs) are promising oxygen evolution reaction (OER) electrocatalysts for alkaline water electrolysis; however, their practical application is often limited by poor electrical conductivity and sluggish charge-transfer kinetics. In this work, a hybrid NiCo-LDH@Mo2CTx/NF electrode was developed by integrating conductive, delaminated Mo2CTx MXene with NiCo-LDH nanosheets that were directly grown on nickel foam via a hydrothermal process. The delamination treatment effectively increased the interlayer spacing in Mo2CTx and provided a conductive platform for the uniform growth of NiCo-LDH, thereby enhancing interfacial contact and electron transport. Structural and surface analyses confirmed the successful formation of the NiCo-LDH@Mo2CTx hybrid architecture with intimate coupling between the LDH and MXene components. Benefiting from the conductive MXene framework and optimized electrode architecture, the NiCo-LDH@Mo2CTx/NF electrode exhibited enhanced OER performance in 1.0 M KOH, requiring overpotentials of 324 and 393 mV to achieve current densities of 50 and 100 mA cm-2, respectively. Furthermore, the hybrid electrode displayed faster reaction kinetics, lower charge-transfer resistance, higher intrinsic activity, and excellent durability, maintaining stable operation for 50 h at 50 mA cm-2. The practical applicability of the catalyst was further validated in an anion exchange membrane water electrolysis (AEMWE) single-cell system. The NiCo-LDH@Mo2CTx/NF anode delivered a current density of 1.15 A cm-2 at 2.0 V and maintained stable operation for 100 h at 500 mA cm-2. These results demonstrate that integrating conductive Mo2CTx MXene with NiCo-LDH is an effective strategy for improving both catalytic activity and operational stability, offering a promising route toward the development of efficient non-precious-metal anodes for alkaline water electrolysis.

키워드