Highly efficient solar water desalination systems based on plasmonic Ni nanoparticles embedded in mesoporous TiO2 scaffold as the photothermal material

Solar water desalination through steam generation is a promising technique with several advantages over conventional methods of water purification. In this work, a low-cost, efficient, and low-carbon footprint solar steam generator is fabricated using a photothermal layer based on non-noble plasmonic nickel (Ni) nanoparticles (Ni NPs). In this regard, Ni NPs are embedded in the mesoporous network of TiO2 NPs as the scaffold (Ni/TiO2 scaff.) via a simple method. Then, Ni/TiO2 scaff. is deposited on the surface of the Ni foam skeleton (named Ni/TiO2 @NF), creating a hydrophilic structure with hierarchical pores. Using the Ni/TiO2 @NF porous structure as the photothermal layer, the incident photons are harvested efficiently, resulting in a remarkable water evaporation rate of 1.43 kgm−2h−1 and a photothermal conversion efficiency of 97 %. By incorporating plasmonic Ni into the TiO2 network, light absorption and heat generation increase because of the localized surface plasmon effect. Remarkably, the devices show no change in their performance even after 8 cycles of operation in real seawater. © 2024