SiO2 nanofiber and graphene oxide assisted fabrication of silica aerogels with novel interpenetration networks for efficient oil adsorption and photothermal evaporation

Aerogels prepared from organosilane are effective for oil sorption due to their elasticity, hydrophobicity and porosity but limited with flame retardancy and thermal stability. In this work, we reported the facile and straightforward fabrication of graphene oxide (GO) composited silica aerogels (SGAG) by simple sol-gel method and ambient pressure drying (APD) using methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) as silane sources, SiO 2 nanofibers (SNFs) and pristine GO nanosheets as the basic templates. The prepared SGAG shows interpenetration networks between core/shell nanofibers and sandwich nanoplates by the deposited silica nanoparticles on the GO and SNFs, respectively. The SGAG exhibits low-density (0.025 g cm −3 ) and high porosity (97.95 %), superhydrophobicity (WCA=159°) and large sorption capacity of dichloromethane as high as 69.35 g g −1 , strong mechanical compressive strength (14.07 KPa) at 80 % strain. Most importantly, the introduced GO provides the SGAG intense light absorption (95.95 %) in the 200–2500 nm and excellent thermal stability and flame retardancy. As a result, the SGAG evaporator shows a high photothermal interfacial evaporation rate of 1.33 kg m −2 h −1 , which expands the application of SGAG for the utilization of solar energy and production of clean water from seawater and wastewater.