Nano-sized heterogeneous photocatalyst Fe₃O₄@V/TiO₂-catalyzed synthesis and antimycobacterial evaluation of 2-substituted benzimidazoles

The 2-substituted benzimidazole has emerged as a promising heterocyclic compound in the field of drug design. In pursuit of more sustainable photocatalysts for 2-substituted benzimidazole synthesis, the method for coating Fe₃O₄ with V-doped TiO₂ was presented. On the base of characterizing composition, morphology, and properties, the prepared nano-sized Fe₃O₄@V/TiO₂ composites were used as a heterogeneous photocatalyst to catalyze the synthesis of 2-substituted benzimidazoles under light. The photocatalyst Fe₃O₄@V/TiO₂ composites showed the enhanced photocatalytic activity compared to no V-doped Fe₃O₄@TiO₂, being able to yield various 2-substituted benzimidazoles in moderate to good yield with recyclability and stability. A possible photocatalysis mechanism was investigated. It was evident that holes, singlet oxygen, and ·O₂̄ radical played important roles in the synthesis of 2-substituted benzimidazole. Moreover, some of the obtained products were demonstrated excellent antibacterial activity.