Highly efficient solar water evaporation of TiO2@TiN hyperbranched nanowires-carbonized wood hierarchical photothermal conversion material

Abstract

Solar water evaporation is a significant technique for water purification, desalination, and distillation. The approaches to obtain low-cost, low toxic and reusable material with high solar water evaporation efficiency are essential to solve the problem of drinking water shortage. Herein, we first synthesize TiO2@TiN hyperbranched nanowires on carbonized wood (CW) for solar water evaporation with a high solar water evaporation rate of 1.5252 kg m−2 h−1 and a solar thermal conversion efficiency about 94.01% under 1 kW m−2 simulated solar irradiation. The outstanding solar water evaporation performance can be contributed to the unique design of combining TiO2@TiN hyperbranched nanowires with CW. TiO2@TiN hyperbranched nanowires have better solar light absorption and higher specific area to evaporate water than TiN nanoparticles and nanotubes. At the same time, the evaporation enthalpy of water in the hyperbranched nanowires deceases obviously compared with that of normal bulk water. Besides, the hierarchical material possesses good stability and high solar evaporation efficiency both in seawater and in deionized water.