Biomass based ultralight monolithic aerogels of two-dimensional nanostructures

The biomass extracted in water after ultrasonic treatment of red pepper powder contributes to the liquid exfoliation of solids such as graphite, hematite, magnetite and silicon and the formation of two-dimensional nanostructures. Afterwards, the amphiphilic biomass acting as a gelator, contributes to the formation of soft hydrogels and the corresponding ultralight monolithic aerogels based on the graphene, hematene, magnetene and silicene nanosheets resulting from the liquid exfoliation. Depending on the basic chemical element of the nanostructures, these novel aerogels exhibited extremely low densities, between 4.22 mg cm −3 with silicene and 14.35 mg cm −3 with magnetene and porosities exceeding 99.7 %. The monolithic ultralight graphene, hematene and magnetene aerogels were fully sustainable as they are derived from natural materials such as minerals hematite, magnetite and graphite, a natural product such as red pepper and water as solvent. Energy consumption for the basic aerogel formation process was also limited compared to other techniques due to the use of short-duration ultrasound. • Red pepper biomass improves exfoliation of graphite, silicon, hematite, magnetite in water. • It promotes the sustainable production of graphene, silicene, hematene and magnetene aerogels. • The aerogels exhibited a porosity of 99.9 % and extremely low density like 4.22 mg cm −3 with silicene.