Acid-doped polyaniline membranes for solar-driven interfacial evaporation

Interface solar desalination technology is an important green and sustainable strategy to solve the freshwater crisis. Herein, polyaniline (PANI) membranes were prepared by immersion precipitation phase inversion (NIPs) method and using for solar-driven water evaporation. To improve the light absorption rate of the PANI membrane, acid doping modification was carried out to the membrane. The results show that the polyaniline-p-toluene sulfonic acid (PANI-PTSA) membrane modified by p-toluene sulfonic acid (PTSA) has microporous structure, and the hydrophilicity was greatly improved after modification. The water evaporation rate and solar energy conversion efficiency of PANI-PTSA membrane were 1.38 kg/(m 2 h) and 80.7% under 1 kW/m 2 sunlight irradiation, respectively, significantly improved compared to the original membrane. Due to the electrostatic repulsion effect of PANI-PTSA on anion charged SO − 3 , Na + is separated from Cl − , which reduces the salt crystallization in the evaporator, indicating that PANI-PTSA membrane has certain salt resistance in solar desalination experiments. This work provides a simple method to prepare the PANI-PTSA membrane with high efficiency and salt resistance that has huge potential for practical application of interface solar desalination technology.