Synergistic NiO–Mn 2 O 3 Composite Thin Films via Facile Dip‐Coating: A Cost‐Effective and Stable Electrocatalyst for Methanol Oxidation in Alkaline Direct Methanol Fuel Cells

ABSTRACT The commercialization of direct methanol fuel cells (DMFCs) is hindered by the high cost, limited durability, and sluggish kinetics of platinum‐based catalysts. To address these challenges, NiO/FTO, Mn 2 O 3 /FTO, and NiO–Mn 2 O 3 /FTO thin films were fabricated using a simple and low‐cost dip‐coating method. Structural and compositional analyses using SEM and EDS confirmed the formation of uniform and porous morphologies, while XRD and Raman spectroscopy verified the crystalline nature and phase formation of the materials. Among the prepared electrodes, the NiO– Mn 2 O 3 /FTO composite exhibited superior electrocatalytic activity for methanol oxidation, delivering a prominent anodic peak at 0.99 V and a maximum current density of 5.8 mA cm − 2 . At 0.65 V, it achieved a current density of 2.5 mA cm − 2 in 1.4 M methanol at a scan rate of 100 mV s − 1 . Chronoamperometric measurements demonstrated good electrochemical stability, with 86% current retention after 2000 s. Electrochemical impedance spectroscopy further confirmed the enhanced charge‐transfer capability, showing a significantly lower charge‐transfer resistance (R ct ) of 71 Ω compared with 349 Ω for NiO and 517 Ω for Mn 2 O 3 electrodes. Overall, the NiO–Mn 2 O 3 /FTO thin film offers a cost‐effective, stable, and efficient catalytic system, demonstrating strong potential as an alternative anode material for DMFC applications.