The treatment of high salt organic sewage is considered to be a high energy consumption process, and it is difficult to degrade organic matter and separate salt and water simultaneously. In this study, a gradient structure titanium oxide nanowire film is developed, which can realize the thorough treatment of sewage under sunlight. Among the film, part TiO2-x has enhanced photocatalytic properties and can completely degrade 0.02 g·L-1 methylene blue in 90 min under 2 sun. Part TinO2n-1 has excellent photothermal conversion efficiency and can achieve 1.833 kg·m-2·h-1 water evaporation rate at 1 sun. Through the special structure design, salt positioning crystallization can be realized to ensure the film's stable operation for a long time. The gradient hydrophilicity of the film ensures adequate and rapid water transfer, while the water flow can induce a significant hydrovoltaic effect. The measured VOC is positively correlated with light intensity and photothermal area and corresponds to the water evaporation rate.
Keywords: TinO2n−1; black titania; hydrovoltaic; photocatalytic; solar steam generation.