Rayleigh-Be<acute accent>nard cells in water-purifying solar stills with rGO/CNT/AgNW solar-energy absorbers

초록

Solar stills are eco-friendly, low-cost, and low-maintenance devices that harness solar energy to evaporate contaminated water and provide distilled pure water condensate in a confined space with a sloped transparent glass cover. While geometry and operating conditions are crucial design factors, the ability to absorb solar energy is the most critical parameter for maximizing water distillation productivity. Here, to enhance light scattering and maximize utilizing solar radiation, the solar energy absorber was nanotextured with reduced graphene oxides (rGO), carbon nanotubes (CNT), and silver nanowires (AgNW), significantly increasing the solar absorber temperature. This efficient solar collection resulted in an improved evaporation and condensation, thereby increasing the output of drinkable pure water. The net temperature increase of Delta T = 11.3 degrees C significantly enhanced convective vapor circulation within the solar still, resulting in a 10.7-fold increase in pure distilled water productivity. Numerical simulations were also conducted for the upper vapor layer under various thermal conditions. The upper vapor layer simulations revealed multiple vortices, which formed a three-dimensional system of Rayleigh-Be<acute accent>nard cells.

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