The acid modified magnetic carbon quantum dots [Fe3O4@CQDs@Si(CH2)3NH@CC@TET@ SO3H] was easily prepared, characterized by the FT-IR, VSM, TEM, SEM, TGA, XRD, and EDX techniques and used as a capable heterogeneous nano-catalyst in a multicomponent condensation reactions for the synthesis of two sets of heterocycles: a) pyridines and b) pyrazoles in high yields and very short reaction times. Also, the prepared new nano-catalyst easily separated from the reaction mixture by a magnet and showed a good catalytic stability and used in six consecutive runs without the significant loss of catalytic activity.
