Invasive plant-derived carbon dots and carbon black co-deposited basalt fiber fabric as an efficient solar interface evaporator for high salinity water purification

Abstract

As global freshwater resources become increasingly scarce, developing novel, highly efficient, and robust photothermal materials for solar interfacial evaporation is vital for alleviating the freshwater crisis. This study proposes an innovative utilization of the leaves from an invasive plant species, Rhus typhina L., as a carbon source to prepare carbon dots (CDs) through hydrothermal synthesis and freeze-drying process. The CDs were then combined with carbon black (CB) and deposited onto basalt fabric (BF) via an immersion coating method to obtain a novel two-dimensional CDs/CB@BF photothermal fabric. The surface morphology, elemental composition, hydrophilicity, and light absorption performance of the prepared fabric were investigated using various advanced characterization techniques. The results showed that the developed material possesses an excellent light absorption property, low evaporation enthalpy (1681 J·g−1), and superior capability for water transportation. More importantly, the CDs/CB@BF evaporator exhibited a remarkable evaporation rate of 2.05 kg·m−2·h−1 in pure water and a high photothermal conversion efficiency of 95.72 % under 1 sun irradiation. Apart from that, the evaporator demonstrated outstanding stability in multiple cyclic tests, and the major ion concentrations after evaporation met the standard for drinking water. The present study provides a new strategy for resourceful utilization and controlling invasive plant species. It also offers an efficient and sustainable way to prepare photothermal materials for solar-driven desalination technologies with broad application prospects.