Work

Dynamic Amorphous Composite Shells on 3D Printed High‐Entropy Alloy Enable Stable and Active High‐Rate Seawater Oxidation

Year: 2025

Type: article

Abstract: The corrosive chloride (Cl − ) in seawater challenges anode stability and compromises the efficiency of oxygen evolution reaction (OER), posing a barrier to high‐rate seawater electrolysis. Herein, selective laser melting (SLM) 3D printing of a high‐entropy NiFeCoCrMn alloy is combined with a 200 s mild anodic acid etching/reprecipitation, to form amorphous hydroxide‐oxide composites on the printed scaffold (a‐SLMH). The grain‐boundary‐free amorphous shells undergo dynamic in situ reconstruction into active NiFeCo oxyhydroxides, while immobilizing Mn/Cr oxides to suppress Cl − attack during OER, as revealed by in situ Raman spectroscopy and ex situ microstructural characterizations. In 1 M KOH + 0.5 M NaCl, the a‐SLMH exhibits leading seawater oxidation performances, such as reaching 500 and 1000 mA cm −2 at low overpotentials of 310 and 328 mV, respectively, and maintaining a 100% O 2 selectivity at 500 mA cm −2 . Critically, the electrode operates stably for at least 500 h in alkaline natural seawater at 500 mA cm −2 , demonstrating its robustness. This work exemplifies that SLM 3D printing coupled with amorphous surface engineering yields durable and active anodes for high‐rate seawater OER.

Source: Small Methods

DOI: 10.1002/smtd.202501777