Rational design of Au–H2Ti2O5 nanowires on Ti foam for Solar-Driven Seawater Evaporation Enhancement

Solar-driven seawater evaporation for seawater desalination is the effective and sustainable solution to utilize solar energy. We designed a hybrid photothermal material composed of Au–H2Ti2O5 nanowires on Ti foam with outstanding photothermal conversion performance to meet the requirement of freshwater shortage. Herein, H2Ti2O5 nanowires were grown on the surface of Ti foam as the substrate and water transfer layer by the hydrothermal method, and then Au nanospheres were deposited on H2Ti2O5 nanowires with the assistance of UV light reduction. The results indicated that the Au-10 material prepared with Au nanosphere deposition of 10 cycles exhibited the excellent solar absorption and photothermal ability, the water evaporation rate and conversion efficiency achieved 4.6800 kg m−2 h−1 and 58.76% under 5 sun irradiation, which was 2.07 times that of the sample without Au deposition. More importantly, the Au-10 showed high stability in the seawater evaporation with nearly lossless photothermal efficiency. The described design strategy of Au–H2Ti2O5 photothermal materials is simple, effective and repeatable, which is suitable for the practical solar-evaporation application. [Display omitted] •Au–H2Ti2O5 nanowires on Ti foam with high photothermal activity were prepared.•The deposition of Au nanospheres significantly influenced the photothermal conversion.•The Au-10 showed high efficiency and stability in the seawater evaporation.