Defect-Induced Self-Cleaning Solar Absorber with Full-Spectrum Light Absorption for Efficient Dye Wastewater Purification

摘要

Solar steam generation is considered a promising approach to provide thesolution for water scarcity. To solve the problem of organic pollutions’ enrichmenton traditional solar absorbers, herein, a self-cleaning absorber, whichconsists of Cs_XWO_3 nanorods-anchored hydrogenated TiO_(2-X) nanowires basedon a flexible Ti mesh (H-TiO_(2-X)/Cs_XWO_3), is proposed. The well-designedH-TiO_(2-X) nanowires grown on Ti mesh contain a rational concentration ratio ofsurface oxygen vacancies (O_V) to bulk O_V, and the introduced W~(5+) and OV inCs_XWO_3 nanorods are also demonstrated. The defects in H-TiO_(2-X)/Cs_XWO_3endow it with a superior photocatalytic activity and light absorption in the fullspectrum. Importantly, the enrichment of organic molecules, both on the surfaceof solar absorbers and in bulk water is carefully studied during solar steamgeneration. Compared with the spatially separated evaporation device withoutphotocatalytic activity, the multifunctional H-TiO_(2-X)/Cs_XWO_3 composite can notonly accomplish a high evaporation rate of 1.46 kgm~(-2) h~(-1), but also prevent thesurface enrichment of dye after continuous 12 h evaporation or after 20 cycletests. Integrating photocatalysis into solar-driven water evaporation optimizesthe performance and broadens the application field.