Sustainable production of clean water: 1 T-MoS2/PDA composite enhanced the photothermal conversion

The scarcity of fresh water resources necessitates us to develop an efficient technique for sustainable production of clean water from seawater and wastewater. Here, we constructed the 1 T-MoS2/PDA (polyaniline) as a photothermal material for purification of seawater and wastewater to produce clean water through interfacial evaporation by virtue of sunlight. 1 T-MoS2 has a higher evaporation capacity of water than 2 H-MoS2, which was selected to prepare 1 T-MoS2/PDA composite for photothermal conversion. As expected, 1 T-MoS2/PDA composite offers a higher evaporation rate of water than both 1 T-MoS2 and PDA, which owes to an excellent light absorbance, low light reflectance and good wettability. Under irradiation of 1 sun, the evaporation rate of water over the 1 T-MoS2/PDA composite in pure water reached 1.51 kg m−2h−1, and the photothermal conversion efficiency reached 92%. Encouragingly, 1 T-MoS2/PDA composite can be well used to treat real seawater and various wastewater such as organic dye solution and heavy metal ion solution, in which the evaporation rate of water is close to pure water, and the quality of water is better than the standard of drinking water established by the World Health Organization (WHO). Besides, 1 T-MoS2/PDA composite still maintain an excellent evaporation performance after treatment of acidic solution and alkaline solution, indicating an excellent durability. This work provides a feasible solution for producing clean water by solar-driven interfacial evaporation from seawater and wastewater.