▎ 摘　　要

Free-standing porous materials with good mechanical properties is quite important in practical applications. Here we develop a two-step process, firstly constructing an electrostatic adsorption surrounding to coat graphene oxide (GO) onto the surface of Ni foam, and secondly utilizing flame to turn it into reduced GO (RGO). RGO is found to closely wrap onto the surface of Ni foam with almost 100% RGO covering rate. As supercapacitor electrode, this RGO-modified Ni foam shows excellent performances in specific capacitance (335.7 F g(-1)), especially in coulombic efficiency (the highest value of 121.9%), energy efficiency (the highest value of 84.6%), and cycle stability (94.4% capacitance retention after 20000 cycles at 40 Ag-1). The growth of alpha-Fe2O3 on this RGO wrapped Ni foam indicates apparently higher specific capacitance (1488.9 mF cm(-2)), energy efficiency, rate capacity, and cycle stability compared with direct growth on bare Ni foam. These outcomes provide new clues for preparing free-standing materials and designing new growth/loading substrates. (C) 2019 Elsevier B.V. All rights reserved.