Preparation of porous magnetic nanocomposites using corncob powders as template and their applications for electromagnetic wave absorption

► We prepared novel porous magnetic nanocomposites using corncob as template. ► The presence of corncob will decrease the bulk density of FeNi alloy from 4.1 to 0.55 g cm−3. ► The optimum matching thickness of the nanocomposites is only 1.0-1.4 mm. ► The nanocomposites show enhanced wide-band absorption for EM waves at 2-18 GHz.