A novel ternary GO@SiO2‐HPW nanocomposite as an efficient heterogeneous catalyst for the synthesis of benzazoles in aqueous media

A new solid acid catalyst, consisting of 12‐phosphotungstic heteropoly acid (HPW) supported on graphene oxide/silica nanocomposite (GO@SiO₂), has been developed via immobilizing HPW onto an amine‐functionalized GO/SiO₂ surface through coordination interaction (GO@SiO₂‐HPW). The GO@SiO₂‐HPW nanocomposite was characterized by Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and powder X‐ray diffraction (XRD). The prepared nanocomposite could be dispersed homogeneously in water and further used as a heterogeneous, reusable, and efficient catalyst for the synthesis of benzimidazoles and benzothiazoles by the reaction of 1,2‐phenelynediamine or 2‐aminothiophenol with different aldehydes.