Effect of CuO, MoO3 and ZnO nanomaterial coated absorbers for clean water production

Solar energy is one of the most powerful sources for many sustainable applications. Recently, efficient water distillation has attracted significant attention. The fresh water productivity depends on how efficiently the system harvests the incoming solar energy and converts it into useful heat. In the present work, nano-coated absorber plates (NCAPs) were examined in the single slope solar still (SSSS) for clean water production. The NCAPs were CuO, MoO3 and ZnO, respectively. The CuO-NCAP was fabricated with the thermal evaporation method while the radio-frequency Magnetron Sputtering technique was used to fabricate the MoO3 and ZnO NCAPs. The attained particle size of the CuO, MoO3 and ZnO are 30–34 nm, 25–30 nm and 30–35 nm, respectively. The sphere (CuO), plate (MoO3), and wedge (ZnO) like morphologies are identified with field emission-scanning electron microscope. All the NCAPs and reference solar still were tested under the same environmental conditions. The climatic parameters (solar influx, ambient temperature and wind) and SSSS’s temperatures including water temperature (Tw), internal air temperature (Tint-air), inner cover (Tic), outer cover (Toc), and absorber plate temperature (TNCAP) were measured at 30 min intervals with the help of Type-J thermocouples. Herein, we present an evaporative heat transfer (hew), efficiency, and cost analysis of the SSSS with CuO, MoO3 and ZnO-NCAPs. Three different feed waters fetched from the surface well water, hill side well water and hill side pond water were used in this work for evaporation. The result reveals that the evaporation of conventional single slope solar still, CuO, MoO3 and ZnO NCAPs were 2.1 l/m2 day, 2.9 l/m2 day, 2.7 l/m2 day and 2.6 l/m2 day, respectively.