3D-carbon dots decorated black TiO2 nanotube Array@Ti foam with enhanced photothermal and photocatalytic activities

Nanostructured titanium oxide semidconductors are considered as potential materials for photothermal and photocatalytic applications. However, investigation on usage of titanium oxide nanotube array lay behind other titanium oxide nanomaterials. In order to change this uneven situation, we reported herein that carbon dots decorated black TiO2 nanotube [email protected] foam (CDs/Black [email protected]) can work as highly efficient device for solar-driven water evaporation and pollutant degradation. Initially, TiO2 nanotube [email protected] foam ([email protected]) was prepared through anodization of Ti foam. Through subsequent hydrogenation treatment and carbon dots decoration, CDs/Black [email protected] was finally achieved. It was found that CDs/Black [email protected] demonstrated three characters including excellent solar light absorption ability, wettability and hierarchical porous structure. For these advantages, photothermal property of [email protected] was stepwise improved. In solar-driven water evaporation experiment, water evaporation rate and solar thermal conversion efficiency attained 1.762 kg m−2 h−1 and 55.3% respectively for CDs/Black [email protected], which are higher than previous reports on titanium oxide nanotube array. CDs/Black [email protected] also exhibited higher photocatalytic property than other samples without hydrogenation and/or carbon dots decoration. The CDs/Black [email protected] is promising for practical applications in solar-driven water evaporation and purification.