Agricultural byproduct/reduced graphene oxide sustainable nanocomposite aerogels as solar evaporation active materials

Abstract

Improving the sustainability of solar evaporation materials can provide new eco-friendly solutions to the growing challenge of clean water availability. This study introduces a new class of sustainable antibiofouling nanocomposite aerogels by incorporating wheat straw (WS), one of the most common agricultural byproducts, into reduced graphene oxide (rGO) aerogels. The WS particles are used without any pre- or post-treatment, eliminating the need for unsafe and costly treatment methods typically required for sustainable aerogel production. Additionally, since WS is inexpensive, this sustainable additive lowers the production costs of rGO-based aerogels when used as a filler. Morphological, textural, and microstructural analyses confirm that the amount of WS added affects both the evaporation interfacial area and the structural properties of the sustainable aerogels. The specific surface areas of rGO-based aerogels with 0.7, 2.2, and 12.5 vol percentages of WS were 147.8 % higher, 23.2 % higher, and 13.2 % lower than the neat rGO aerogel, respectively. This variation in microstructure resulted in the solar evaporation efficiency of these nanocomposite aerogels being 16.1 %, 9.2 %, and 1.2 % higher than that of the neat rGO aerogel, respectively. Moreover, the estimated material costs of these sustainable aerogels were 0.7 %, 2.2 %, and 12.6 % lower than those of the neat rGO aerogel, respectively. Additionally, antibiofouling studies against Nitzschia demonstrated that incorporating WS into the rGO aerogel structure can improve microorganism growth inhibition by more than 10 %. Therefore, the integration of WS into the 3D rGO framework enables the development of cost-effective photothermal active materials for solar evaporation applications.