3D‐Printed Porous High‐Entropy Alloy Boosts Peroxymonosulfate Activation for Long‐Term Organic Pollutant Degradation

ABSTRACT High‐entropy alloys (HEAs) have attracted considerable interest from researchers owing to their tunable chemical compositions, exceptional structural stability, and promising catalytic properties. However, their large‐scale application is often hindered by complex manufacturing techniques and poor durability. Herein, we report a simple and cost‐effective three‐dimensional (3D) printing strategy to fabricate a 3D‐FeMnCrCo HEA catalyst with precisely controlled composition, structure, and porosity. The as‐prepared 3D‐FeMnCrCo catalyst exhibits high printing accuracy, excellent compression resistance, and remarkable efficiency in degrading organic contaminants using peroxymonosulfate (PMS) activation. Notably, the catalyst maintains outstanding catalytic stability over 100 consecutive cycles, which outperforms most of its powdered counterparts. Theoretical calculations and controlled experiments reveal that a synergistic combination of Fe/Mn electron donation, Co‐mediated charge buffering, and Cr‐driven orbital hybridization lowers the electron transfer energy barrier, thereby enhancing PMS activation. Mechanistic studies further show that singlet oxygen is the predominant reactive species in the 3D‐FeMnCrCo/PMS system. The biotoxicity of degraded pollutants and the catalyst's performance in treating actual wastewater are also systematically evaluated. This work provides critical insights into the practical application of HEAs in water treatment and guides the design of efficient, stable, and easily recoverable catalysts for environmental remediation.