Boosting-photothermal properties of Cu/Black TiO₂ nanoparticles on biomimetics texture structure as high-performance and self-regenerating solar-evaporator

To address the global water crisis, solar vapor generation emerged as a promising technology for clean-water uptake from seawater. Black TiO2 with wide-spectrum absorbancy, non-toxicity, cost-effectively, and chemical stability has attracted great interest in efficient solar-driven evaporators. Herein, the black TiO2 nanoparticles were synthesized through one step and facile reduction process of white oxide powder squeezed between two layers of NaCl. The prepared powder was deposited on the bare and copper-treated cotton fabrics as light absorbers in the proposed solar steam generation (SSG) systems. Various structural and morphology characterization methods have been utilized to verify of synthesis procedure. Heat localization was performed by the floated yarn-stitched polyurethane (PU) foam as a holder for the fabrics. Continuous water transmission from the saline water container to the evaporation surface was done via capillary forces in the yarns. The hybrid absorber introduced a superior solar-thermal conversion efficiency of about 98.56 % and 1.94 kg.m(-2) h(-1) evaporation rate which was 3.13 times larger than the control one. Antifouling and recyclability properties of the samples were studied in outdoor conditions. The suggested hybrid-based (Cu/black TiO2) SSG with significant properties of simplicity, non-toxicity, and high evaporating activity opens new shortcuts toward green water desalination and also salt extraction demands.