Low Cost, Robust, Environmentally Friendly Geopolymer-Mesoporous Carbon Composites for Efficient Solar Powered Steam Generation

High-efficiency, environment friendly, renewable energy-based methods of desalination represent attractive and potentially very powerful solutions to the long-standing problem of global water shortage. Many new laboratory-scale materials have been developed for photothermal desalination but the development of low-cost, easy-to-manufacture, and scalable materials and systems that can convert solar irradiation into exploitable thermal energy in this context is still a significant challenge. This paper presents work on a geopolymer-biomass mesoporous carbon composite (GBMCC) device with mesoporous and macroporous structures for harvesting solar energy, which is then used in a device to generate water vapor with high efficiency using negative pressure, wind-driven, steam generation. The GBMCC device gives water evaporation rates of 1.58 and 2.71 kg m(-2) h(-1) under 1 and 3 suns illumination, with the solar thermal conversion efficiency up to 84.95% and 67.6%, respectively. A remarkable, record high water vapor generation rate of 7.55 kg m(-2) h(-1) is achieved under 1 sun solar intensity at the wind speed of 3 m s(-1). This is a key step forward todays efficient, sustainable and economical production of clean water from seawater or common wastewater with free solar energy.