Superior broadband sound absorption in hierarchical ultralight graphene oxide aerogels achieved through emulsion freeze-casting

•A hierarchical porous ultralight graphene oxide (GO) aerogel was fabricated.•The aerogel was formed through emulsion freeze casting of an air-in-water emulsion.•The GO aerogel showed superior average absorption coefficients of up to 0.86.•Numerical models were developed to analysis the acoustic properties of the aerogel.•High reticulation rates of the aerogel facilitate effective sound dissipation.