A novel organic–inorganic hybrid of 2,2′-bipyridyl (2,2′-bipy) linked covalently with the first inorganic framework based on boron-containing Keggin-type heteropolymolybdate anion [BMo12O40]5− has been hydrothermally synthesized in aqueous solution. The crystal structure was fully characterized by elemental analyses, single crystal X-ray diffraction, Fourier-transform infrared spectrum (FT-IR), powder X-ray diffraction (XRD), Ultraviolet–visible spectroscopy (UV–Vis) and electron paramagnetic resonance (EPR) analysis. The catalytic performance of the synthesized catalyst was studied in degradation of methylene blue (MB) at ambient temperature. The catalyst exhibited excellent degradation against MB with a rate constant of 0.506/m, which was much higher than those by other polyoxometalate catalysts. Moreover, it was found to be easily separated from the reaction solution and recycled up to five times without significant loss of degradation activity.