Selective Deposition of Candle Soot on Cellulose Membrane for Efficient Solar Evaporation

Abstract

Effectively utilizing eco-friendly solar energy for desalination and waste water purification has immense potential to overcome the global water crisis. Herein, we demonstrate a highly efficient solar vapor generator (SVG) developed via a simple morphological alteration, from a two-dimensional (2D) TiO2 film (TF) to one-dimensional (1D) TiO2 nanorods (TNRs) grown on a glassy carbon foam (CF). Given that evaporation is primarily a surface physical phenomenon, the 1D morphology of TNRs provides a higher evaporation surface area compared to its 2D counterpart. Additionally, the super hydrophilic nature of TNRs ensures an adequate supply of water to the evaporation surface via effective capillary action. Consequently, the 1D TNRs properly utilize photothermal heat, which results in a significant reduction in the convection heat loss. Owing to the synergistic effect of these characteristics, TNRs/CF acquired a high evaporation rate ~2.23 kg m-2 h-1 and an energy utilization efficiency ~67.1% under one sun irradiation. Moreover, the excellent stability, desalination and self-cleaning capabilities and the facile fabrication method make TNRs/CF suitable for the cost-effective, large-scale device application.