Black titania coated glass fiber as a photo absorber in interfacial solar steam generation under harsh condition

Abstract

Interfacial solar steam generation (ISSG) is one of the promising solutions in the field of water filtration, desalination, and solvent recovery. For the industrial applications of the technology, there is a need for developing highly durable, thermally stable, and inert light absorbers. Therefore, this work addresses this issue by synthesizing black Titania (B–TiO2) via vacuum annealing and depositing it on glass fiber (GF) via vacuum filtration with an ethyl cellulose binder. According to the characterization techniques analyses, the change of colour is attributed to the occurrence of oxygen vacancies in the surface layers of TiO2 nanoparticles during vacuum annealing. The deposition parameters were optimized for achieving a maximum solar-weighted light absorptance of 95.7%. The optimized B–TiO2 GF was applied for the steam generation experiments and achieved the evaporation rate of 1.53 kg m−2 h−1, which corresponds to solar-steam conversion efficiency of 97.7 % under standard measurements condition of AM 1.5 G sun and ambient temperature and relative humidity of 20 °C and 40% respectively. Thanks to the high durability and chemical inertness of B–TiO2 GF it was applied for water filtration in extreme conditions of acidic/alkaline water and high-sun illumination (up to 35-sun). Worth noting that for high-sun experimentation there is a need to use a binder to improve particle attachment to the glass fibers.