With the water and energy crises becoming critical issues for an increasingly industrialized society, solar-driven water purification technologies are highly desired for both potable water production and wastewater treatment. Herein, the performance of an integrated photocatalytic and photothermal composite, TiO2/Au-carbon nanotube (TiO2/Au-CNT)-coated SiC ceramic plate, in complex contaminated water treatment driven by solar energy is investigated. The short-wavelength part of the solar spectrum is used for simultaneous photo-oxidation of rhodamine B (RhB) (oxidation efficiency of ≈98.5%) and photo-reduction of Cr(VI) (reduction efficiency of ≈90.6%) in an integrated solar still device. A Z-scheme charge transfer mechanism with CNTs as an electron mediator is proposed and discussed for TiO2/Au-CNT-coated SiC ceramic plate. Meanwhile, the design here allowed the long-wavelength part of the solar spectrum to be utilized for high-quality potable clean water production via solar distillation with a solar-to-water evaporation efficiency of ≈72%. Therefore, this integrated photocatalytic and photothermal system can be utilized for potable water production and wastewater treatment in the same device with high solar energy utilization efficiency.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This project is based upon work supported by the King Abdullah University of Science and Technology (KAUST) Center Applied Research Fund (CAF) awarded to the Water Desalination and Reuse Center (WDRC).