A literature review on the effect of using porous materials and Nanoparticles on improving of the performance of solar stills

Drinking water scarcity has become one of the main challenges of human societies in recent years. Most of the water resources are stored as the non-drinkable saline water or are frozen in the poles. Therefore, they cannot be used directly for drinking. This issue indicates the importance of using appropriate techniques for water purification. One of these techniques is the usage of solar stills that can be used in remote tropical areas. The simple structure, low cost of manufacturing, and the usage of solar energy as a clean source is some benefits of this kind of equipment. The main problem of solar stills is their low efficiency. The researchers in this field used many active and passive methods to increase the efficiency of this device. In this research, two passive techniques used for enhancing the efficiency of solar stills containing usage of porous materials and nanoparticles are reviewed. The results of the research in these fields are briefly presented. Finally, based on the literature review, some suggestions for future works are provided.