Self-powered seawater desalination and electrolysis using flowing kinetic energy

Abstract Fresh water for human daily life is an important resource of the world, which could be as precious as oil in many cases. The increased needs for fresh water are becoming a major challenge to the quality of our life. Recently much attention has been paid to the seawater desalination with low energy cost. Here we report a seawater desalination (SD) and electrolysis (SE) system on the basis of the newly invented triboelectric nanogenerator (TENG). The TENG consists of radial arrays of micro-sized sectors on the contact surfaces and exhibits a high output current of 3.3 mA. 0.5 M salt solution was desalinated to form drinking water in 16 h and the desalination rate reached 98.3%. Subsequently, a totally self-powered SD and SE system driven by the kinetic energy of flowing water was presented. Using the power generated by flowing water at a rate of 40 L min −1 , the desalination rate reaches 8.2% in 3 h. Furthermore, the byproduct of concentrated salty water was split at a hydrogen production rate of 2.6×10 −5  mL s −1 . Our study demonstrates an innovative and unique approach toward a total self-powered SD and SE system. This is an important step toward self-powered environmental electrochemistry.