FeCoNiMnMo high-entropy alloy/carbon microspheres constructed via MOF-derived spray-drying granulation for enhanced oxygen evolution reaction

Abstract

The development of efficient and durable oxygen evolution reaction (OER) electrocatalysts based on non-precious metals is crucial for advancing water-splitting technologies. Herein, we report a rational design and synthesis of FeCoNiMnMo high-entropy alloy(HEA) nanoparticles within hierarchical porous carbon microspheres (denoted as FeCoNiMnMo/C-MS) via a metal–organic framework (MOF)-derived spray-drying strategy. This method ensures atomic-level homogeneity of the metal precursors and constructs a unique microsphere architecture. Comprehensive characterization confirms the formation of a single-phase face-centered cubic (FCC) HEA with uniformly distributed elements. When evaluated as an OER catalyst, the FeCoNiMnMo/C-MS exhibits exceptional performance in alkaline media, requiring low overpotentials of only 380 and 406 mV to achieve current densities of 500 and 1000 mA cm⁻², respectively. It also demonstrates outstanding long-term stability, maintaining operation for over 400 hours at 400 mA cm⁻². The superior performance is attributed to the synergistic combination of the multi-element HEA core, which provides high intrinsic activity, and the porous carbon microsphere host, which facilitates mass transport and ensures structural robustness. This work presents a scalable synthesis route for high-performance non-precious OER catalysts.