Nano-sized heterogeneous photocatalyst Fe 3 O 4 @V/TiO 2 -catalyzed synthesis and antimicrobial evaluation of 2-substituted benzimidazoles

Abstract 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 proved to have excellent antibacterial activity.