Efficient and versatile catalyst for nitrobenzene compounds reduction based on magnetite coated with semi-metallic bismuth

Developing low-cost catalysts for the reduction of nitrobenzene compounds is crucial for advancing industrial applications and environmental remediation processes. We report the synthesis of metallic bismuth supported on magnetite nanoparticles. The material was evaluated as a catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using NaBH₄ as the reducing agent, demonstrating high catalytic activity by converting 4-NP into 4-AP within just 1.0 min. The catalyst exhibited a first-order kinetic constant 72 times higher than the magnetite control. The effects of reaction temperature and reactant concentration were investigated. After the reaction, the catalyst was easily removed from the reaction system using a magnet and was efficiently reused for four additional cycles. Mag-Bi was efficient as a catalyst for the reduction reaction of other nitrobenzene compounds, including 4-nitrotoluene, 1-chloro-4-nitrobenzene, and 2,4-dinitrophenol. Overall, these results suggest that Mag-Bi is a promising catalyst for nitroarene reduction, exhibiting excellent catalytic performance and good recyclability.