Industrialized Bimetallic Nanosheets for Efficient Electro‐Degradation of Methyl Orange

ABSTRACT

The treatment of azo dye wastewater remains a significant challenge due to the lack of electrode materials that simultaneously offer high catalytic efficiency, low cost, and scalable preparation. To address this bottleneck, this study develops an in‐situ grown nickel‐iron layered double hydroxide (NiFe‐LDHs) electrode synthesized via a simple immersion method at ambient temperature and pressure on a nickel foam substrate (NiFe‐LDHs/NF), with a material cost of approximately 0.69 Yuan/cm ² . Using methyl orange (MO) as the model pollutant, the effects of electrolyte type and concentration, applied voltage, initial pH, and temperature on degradation efficiency were systematically investigated. Under the optimal conditions, a degradation efficiency of 99.95% was achieved for 100 mL of 10 mg/L MO solution within 25 min. Total organic carbon and chemical oxygen demand analyses confirmed the efficient mineralization of MO into CO ₂ and H ₂ O. Radical scavenging experiments combined with error analysis quantitatively determined the contribution of hydroxyl radicals (·OH) to be 57.6% and sulfate radicals (SO ₄ ⁻ ) to be 31.3% toward the overall degradation. The electrode maintains excellent stability under polarity reversal conditions. With its simple preparation process and low cost, this work provides a scalable technical solution for the industrial treatment of recalcitrant azo dye wastewater.