Regulation of the activity interface in Ni–Co–Mn ternary aerogel catalysts for efficient water splitting

Abstract

Extensive studies have demonstrated that multi-element doping can effectively modulate the surface electronic structure of catalysts, significantly enhancing their catalytic performance beyond their single-element counterparts for water splitting. However, the fundamental mechanisms governing how distinct elemental compositions influence the activity-stability trade-off remain insufficiently explored. Inspired by the compositional engineering strategy used for Ni–Co–Mn ternary cathodes (Li(Ni_xCo_yMn_1−x−y)O₂, denoted as NCM) in lithium-ion batteries, we systematically investigated NCM aerogel catalysts with varying stoichiometric ratios (NCM111, NCM523, NCM622, and NCM811) for bifunctional water electrolysis. DFT calculations reveal that Ni–Co–Mn can synergistically modulate the charge distribution of the multimetallic matrix, thereby optimizing the adsorption energetics of reaction intermediates. Electrochemical evaluations demonstrate that NCM111 achieves balanced activity and durability, delivering competitive overpotentials of 198 mV for the HER and 358 mV for the OER at 20 mA cm⁻² in alkaline media. This work provides a viable strategy for designing cost-effective, high-performance bifunctional catalysts through rational multi-element coordination, providing a materials-innovation bridge between energy storage and conversion technologies.