Candle soot nanoparticle-decorated wood for efficient solar vapor generation

Vapor generation by means of harvesting solar energy is an energy-saving, environmentally friendly and efficient method to achieve seawater desalination and water purification. However, solar vapor generation is subjected to poor utilization efficiency of solar energy or it depends on expensive solar absorption materials and complex processes. In this work, inspired by tree transpiration in nature, a novel wood-based vapor generator composed of wood substrates with 3D microchannels and a candle soot decoration surface was designed and developed. Profiting from the simultaneous optimization of the candle soot-decorated wood (CS-wood) properties (hydrophilic wood substrates with microchannels for water transportation and escape, low heat conduction value, and a black CS decoration surface with high solar absorbing abilities), the as-fabricated CS-wood vapor generation material achieved a relatively high net evaporation rate value of 0.950 kg m−2 h−1 when being illuminated at one sun. This bilayer wood-based vapor generator exhibited good capacities of desalination (seawater) and purification (lake water). Such wood-based material as a high-performance, cost-efficient and scalable vapor generator can be a potential candidate for the production of clean water to alleviate the global clean water shortage crisis via the effective utilization of green energy.