A dual-functional vertical oriented C/TiO2 nanotubes for superior solar evaporation of sewage treatment

Although the solar interfacial evaporation technology with the advantages of outstanding photothermal conversion, easy availability and high freshwater production, their photothermal materials still face the problem of contaminated by the organic pollutants in the raw waters such as sewage and natural water. Herein, we present a vertically oriented hierarchical C/TiO 2 nanotubes with bifunction of photocatalytic degradation of pollutants and freshwater production via photothermal effect synchronously. The carbon nanoparticles of the hierarchical C/TiO 2 nanotubes not only broaden the range of sunlight absorption to accelerate the water evaporation, but also reduced the recombination of electron-hole significantly to improve the photocatalytic efficiency. Meanwhile, the excellent water transportation via unique arranged arrays vertically, the abundant active sites derived from hierarchical structure, the vertical oriented C/TiO 2 nanotubes exhibit a large solar-driven water evaporation rate of 1.59 kg m −2  h −1 and the methyl orange (MO) photodegradation efficiency of 92.9 % for the underneath sewage under 1 sun illumination synchronously. These findings have great potential applications in solar-powered production freshwater from wastewater and natural waters such as rain and river water.