Ag/polypyrrole co-modified poly(ionic liquid)s hydrogels as efficient solar generators for desalination

Solar steam generation is one of the most promising technologies to utilize solar energy, which is applied to extract fresh water from seawater or contaminated water. However, solar vapour generation is usually restricted to the underutilization of solar energy or depends on complicated light-harvesting adjuncts. Here, a novel hierarchically double-layered evaporation device was demonstrated based on poly(ionic liquid)s hydrogel with the upper surface co-modified by polypyrrole (PPy) and silver particles (named as Ag/PPy-PMBA-BrILs). The evaporation system exhibits a cooperative interaction of the double-layer with efficient light-absorbing and water transportation, leading to a high evaporation rate of 1.37 kg m−2 h−1 with a photothermal conversion efficiency of 88.7% under 1 sun illumination. The high evaporation rate is mainly due to the synergistic light absorption of polypyrrole and silver particles as well as the excellent water transfer capability of poly(ionic liquid)s hydrogel. Moreover, the hydrogel-based evaporation device also exhibits excellent salt-resistant performance for solar desilination in artificial sea water. The high-efficiency poly(ionic liquid)s hydrogel based solar steam generator with co-modified light-absorbing surface may open new opportunities for the future design and fabrication of high-performanced solar steam generator for practical applications.