الفهرس 
Chapter 1 IntroductionOnly 14 pages are availabe for public view
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Abstract
Freshwater scarcity and energy shortage have become two of the most fundamental global challenges. Although water covers three-quarters of the Earth’s surface, 97.5% is undrinkable saline water including seawater, wastewater, and brackish water. Freshwater lack all over the world is due to population growth, environmental pollution, agricultural activities, industrial expansion, and abuse of water usage. Currently, several seawater desalination technologies exist, including multiple effect distillation, electro-dialysis, multi-stage flash distillation, capacitive deionization, reverse osmosis, and desalination batteries. These dominant strategies require electrical energy more than 0.4% of the worldwide electricity generation capacity. Innovative desalination strategies that would minimize energy use and costs are in persistent need, such as the solar evaporation technique that uses free and abundant solar energy to produce fresh water from brackish water, seawater, and contaminated water. The solar steam generation (SSG) technique will have various applications in industry and power plants to reduce the production cost. Typically, the interfacial evaporation system consists of a bilayer configuration, in which the bottom supporting layer is used to pump water to the top layer as well as reduce heat loss, and the top layer is a photothermal material used to promote the sunlight absorbability and improve the efficiency of solar thermal conversion. Photothermal materials used in the SSG system can efficiently collect solar light and convert it to thermal energy to heat the water at the interface in place of directly heating bulk water to lower heat loss and enhance the efficiency of light-to-vapor conversion. The absorption of broadband light, the high wettability and cost-effectiveness of the photothermal layer are the key issues required for high-efficiency solar desalination. The currently employed photothermal materials for solar desalination are metals with surface plasmon resonance (SPR) absorption which show over 95% absorption of sunlight. Plasmonic metals have been demonstrated for efficiently heating water to temperatures above the boiling point of water. Most recently, metal nanoparticles, especially gold, silver, alumina, and other nanoparticles have been proposed for steam water generation under solar irradiation. Part 2. Experimental: Synthesis of solar steam generation device and three series of photothermal materials such as (Plasmonic silver and copper/ biochar, P-g-C3N4/ biochar /graphene oxide. characterization of the as-synthesized photoabsorbers by FT-IR, UV-vis, XRD, TEM, SEM, XPS and surface wettability. Part 3. Results and discussion. In this part, we discussed the results from the characterization analysis which approved the successful synthesis of the photothrmal materials. Also, we discussed the results of the solar desalination of these photothermal materials in distilled water and saline water. We tested the solar desalination in natural seawater. We discussed thr results of the solar desalination of the dye, acidic, alkaline seawater. The solar desalination was tested under real sun. The results indicated that the as-synthesized photothermal materials possesses a high evaporation rate and efficiency. Also, it indicated that the solar desalination of the contaminated seawater produces freshwater which can be used for human life.