Solar evaporation enhancement by a compound film based on Au@TiO2 core-shell nanoparticles

Solar water evaporation attracts much attentionowing to its widespread applications, including in power generation, seawater desalination, wastewater treatment, and clean water production. A multilayer thin film with a physically combined structure has been designed to achieve multi-functionality. However, this film leads to a decline in the evaporation capacity because of the mutual influences of different layers. In this work, a compound film based on Au@TiO2 core-shell nanoparticles was designed and fabricated for achieving highly efficient solar water evaporation. The effects on solar evaporation enhancement of different evaporation styles, nanoparticle films, and light intensities were determined by solar evaporation experiments. It was found that the core-shell nanoparticle film showed better solar evaporation enhancement than the suspension of Au@TiO2 core-shell nanoparticles, films based on solely Au or TiO2 nanoparticles, and multilayer thin films of Au and TiO2 nanoparticles because of the formation of a core-shell nanostructure. The solar evaporation enhancement achieved by the Au@TiO2 core-shell nanoparticle film could simplify the film structures, reduce costs, and expand their applicability. (C) 2017 Elsevier Ltd. All rights reserved.