Porous stainless steel supported magnetite crystalline membranes for hexavalent chromium removal from aqueous solutions

► Magnetite crystalline membranes on porous stainless steel for Cr (VI) removal. ► We examine the impact of the fabrication parameters and removal performance. ► Cubic grain under layer and pillar grain top layer membranes are achieved. ► Grain shapes depend on the relative of nucleation and crystal growth rates. ► The elimination efficiency for Cr (VI) removal is 92.5%.