Salt‐Template Assisted Aerosol Jet Printing of FeCo Bimetallic Nanosheets as Efficient Oxygen Evolution Catalysts

Abstract

Iron–cobalt (FeCo) catalysts are promising as an alternative to noble‐metal electrocatalysts for the oxygen evolution reaction (OER), but achieving uniform deposition with strong substrate adhesion and well‐defined hierarchical structure is still a major challenge. Herein, a facile route involving aerosol jet printing (AJP), annealing, and template water leaching enables the direct fabrication of self‐supported Fe–Co bimetallic nanosheets on carbon fiber paper (CFP). This approach creates an integrated electrode with a 3D open‐framework architecture and ensures intimate contact between the catalyst and the current collector. Consequently, the catalyst shows improved OER performance in 1 M KOH, requiring an overpotential of 271 mV to reach 20 mA cm −2 , with a Tafel slope of 54.8 mV dec −1 . The activity is attributed to the synergistic coupling of the hierarchical nanosheet morphology, the bimetallic synergy between Fe and Co, and the superhydrophilic surface chemistry that enhances mass transport. This work provides a useful proof‐of‐concept for constructing self‐supported OER electrodes by coupling spatially controlled AJP deposition with NaCl‐template engineering.