Hollow SiO₂ microspheres in-situ doped poly(ionicliquid)s gels as efficient solar steam generators for desalination

Solar steam generation (SSG) is one of the promising technologies for seawater desalination and contaminated water purification. However, SSG devices are always restricted by poor insulation performance, insufficient solar spectrum absorption and serious salt-fouling. Here, a double-layered novel SSG system was fabricated by using poly(ionicliquid)s gels with hollow SiO₂ microspheres in-situ doping to enhance the thermal insulation of lower layer, and co-modified the top surface by polypyrrole (PPy) and silver particles to strengthen the solar absorption capability. Benefiting from the low thermal conductivity (0.082 W m^-1 k^-1), strong light absorption (ca. 96%) and adequate water transport capability of poly(ionic liquid)s gels. As SSG device, a superb photothermal conversion efficiency of 90.5% is achieved under 1 sun illumination. Moreover, the poly(ionic liquid)s gels based SSG system also shows good desalination performance in artificial sea water and high concentration brine, and the purified water from artificial seawater can achieve the WHO's standard for drinking water. Therefore, this work combined attractive in-situ doping and co-modified strategies for fabricating high performance and thus shows significant potential for real applications.