A facile approach is developed to mass produce porous 3-D bulk metallic nanostructure with high purity,fine nanostructures of high specific surface area,and improved mechanical performance,at a low cost and high production rate.This approach is based on an effective mechanical pretreatment method(surface mechanical attrition techniques,SMAT)and the convenient dealloying technique.It was found that this novel approach is able to effectively remove the reactive metal at an accelerated rate,and greatly improve the morphology of the porous metallic framework,leading to 3-D bulk nanoporous structures.The porous Cu-based nanostructures obtained using this method showed superior performance for supercapacitor electrodes.