An eco-friendly route to magnetic silica microspheres and nanospheres

► A green alternative to obtain magnetic silica (MS) beads has been designed. ► Polydisperse microspheres or monodisperse nanospheres can be obtained. ► The nanocomposites compare well with MS beads synthesized by conventional methods. ► Hybrid MS microspheres modified by mercaptoporpyl moieties can also be prepared. ► Inorganic and hybrid MS microspheres were tested as adsorbents for heavy metals.