An easily scalable multi-unit solar/wave-driven interfacial evaporation system connected by a hinge-like structure for co-producing of fresh water and electricity

• Developed a multi-unit solar/wave driven interfacial evaporation system (MSWDIES) • Developed a novel piezoelectric membrane with good ability of converting wave energy. • MSWDIES can produce water and electricity and is scalable by novel hinged structure. • MSWDIES reached 1.46 kg m -2 h −1 of evaporation and 1.01 W m −2 of electrical output. Solar-driven interfacial evaporation (SDIE) has become an innovative and sustainable technology for seawater desalination to produce fresh water, and its integration with other energy conversion technologies (photoelectric, piezoelectric, etc.) for power generation, wastewater treatment, etc. has attracted increasing attention. In this work, a light absorber based on nickel foam-loaded CNTs doped with TiO 2 and Ag is fabricated, which can utilize solar energy at different wavelengths, by simultaneous photothermal and photoelectric conversion; Meanwhile, a BT-P(VDF-TrFE) piezoelectric film is formed via P(VDF-TrFE) doped with BaTiO 3 (BT); these two layers, together with the thermal insulating water transport layer and the electrode, form the solar/wave driven interfacial evaporation unit (SWDIEU), which produces fresh water and electricity. Besides, a hinge-like structure is designed to connect and extend the SWDIEU to solve the problem of piezoelectric layer deformation limited by other structures. The piezoelectric voltage of the 2-unit system is increased by 45 times and the power density of 489 times compared to the single-unit system, making the integrated system easily scalable. The system achieves an evaporation rate of 1.46 kg m -2 h −1 and an electric power output of 1.01 W/m −2 under 1 sun and 1 Hz waves, and is capable of organic wastewater treatment.