Efficient solar steam generation by using metal-versatile hierarchical nanostructures for nickel and gold with aerogel insulator

•Broadband solar absorbing surfaces were fabricated by Ni or Au deposition on hierarchical nanostructures.•Ni deposited surface shows high solar absorptance of 0.90 which can replace noble metal (Au, 0.92)•Solar steam generation experiments were conducted with Ni or Au deposited hierarchical nanostructures.•Solar steam generation efficiency was increased by heat localization using aerogel as thermal insulator.