Highly-performance polyimide as an efficient photothermal material for solar-driven water evaporation

Solar interfacial evaporation, as an efficient sustainable technology for clean water production, is conducive to mitigate the problem of global water shortage. The development of highly efficient photothermal materials, however, remains a challenge. In this work, we report a photothermal material of polyimide (PI) coupled with carbon nanotube (CNT). The PI is synthesized from in-house diaminocyanostyrene and commercial pyromellitic dianhydride (PMDA) to absorb UV and visible light. The CNT complementarily absorbs NIR light in the solar spectrum. Upon integration with glutaraldehyde crosslinked cellulose (G-CNF) as the waterway and polyurethane (PU) as the heat insulation layer, the PI/CNT-based three-dimension (3D) interfacial steam generator exhibits high solar energy absorption efficiency. The steam evaporator shows a water evaporation rate of 1.58 kg m −2 h −1 and high stability against salinity and pH variations, providing a potential portable technology for water purification. • A novel intrinsic polyimide with efficient solar-to-heat conversion is designed and fabricated. • The well-designed 3D interfacial steam generator based on self-made PI coupled with carbon nanotube (CNT) shows good structural stability and cost effectiveness. • The 3D interfacial steam generator shows high photothermal efficiencies and high evaporation rates over 1.58 kg m −2 h −1 .