Coating of Wood with Fe2O3-Decorated Carbon Nanotubes by One-Step Combustion for Efficient Solar Steam Generation

As the global water shortage becomes increasingly serious, it is highly imperative to develop efficient, renewable, and large-scale water purification devices. Herein, an efficient solar-driven water purification device of wood coated with Fe2O3 nanoparticle-decorated carbon nanotubes (Fe2O3/CNT) is fabricated in only a few seconds by one-step combustion of ferric acetylacetonate in an ambient environment. The thin layer of the Fe2O3/CNT hybrid coated on the upper surface of the wood serves as a solar-light absorber for converting solar energy to thermal energy, while the thermally insulating wood layer with vertically aligned channels endows the device with rapid water upward transport and localizes the generated heat inside the Fe2O3/CNT layer for solar-driven water evaporation. As a result, the wood/Fe2O3/CNT device achieves a high water steam generation capability of 1.42 kg m–2 h–1 along with an excellent evaporation efficiency of 87.2% under 1 sun irradiation, higher than most of the wood-based solar-driven water evaporation device reported. This device is also efficient in the purification of seawaters and wastewaters. This work demonstrates a rapid and facile methodology for large-scale fabrication of wood/Fe2O3/CNT devices for efficient solar-driven water purification.