• • Ball-milled Fe/DBC composite (BM-Fe/DBC) achieved 79.9% nitrobenzene removal at Fe:C mass ratio 2:1, dosage 1.0 g·L−1, pH 5, outperforming physically mixed composite (PM-Fe/DBC) and demonstrating the critical role of interfacial Fe–C coupling.
• • Aniline yield from BM-Fe/DBC was 1.85 times higher than that from PM-Fe/DBC, indicating enhanced electron selectivity toward nitrobenzene reduction over competing hydrogen evolution.
• • Electrochemical analysis revealed that BM-Fe/DBC exhibited a corrosion current density approximately 2.15 times higher and lower charge transfer resistance than PM-Fe/DBC, confirming superior electron transfer kinetics.
• • BM-Fe/DBC maintained high reduction efficiency across a wide pH range (3–9), overcoming the strong pH dependency typically observed for bare ZVI, which is critical for practical wastewater treatment under variable pH conditions.