Abstract
The present study evaluates the potential use of graphene oxide (GO) and reduced graphene oxide (RGO) additives to improve the photothermal response and evaporation rates of basin water used in solar thermal stills. The prepared GO-based and RGO-based test solutions were dilute, well dispersed, and stable. Improvements in photothermal response and evaporation rates were found to be significant. The best-performing fluid was the 30% RGO stock solution-based water solution, which achieved a temperature enhancement of 5.2% and a significant evaporation rate improvement of 30.5% compared to pure water samples. Importantly, the evaporation rates achieved were at relatively lower solution temperatures that were typically between 39 and 41 °C, thus highlighting the advantage of adding either GO or RGO to basin water to improve evaporation rates for solar thermal stills operating at lower temperatures. All GO- and RGO-based solutions displayed excellent dispersion stability over the investigated temperature range.