Salt-resistant solar still based on hollow sphere porous ionic polymers for desalination

Abstract

The exploitation of photothermal materials (PM) with desired salt-resistance is significant importance for solar steam generation (SSG). Herein, a novel salt-resistant PM based on porous ionic polymers（PIPs）coated with acetylene black (AB) was prepared for efficient SSG (named as PIPs-AB). The PIPs were synthesized using alkynylbenzene and ionic monomers as building blocks by Sonogashira-hagihara cross coupling reaction, which show low thermal conductivity (0.1 W m−1 K−1) and super hydrophilicity (infiltration within 40 ms). By decorated with AB, an excellent light absorption of 90% for the as-prepared PIPs-AB was obtained. Coupling with their superior thermal insulation and desired water transportation ability, the as-prepared PIPs-AB exhibits superior solar conversion efficiency (85.4% under 1 sun illumination). Furthermore, the intrinsically ionic feature of PIPs, combining with the Janus structure composed of superhydrophilic PIPs monolith and hydrophobic AB coating, makes the PIPs-AB excellent salt-resistant ability, e.g. no salt accumulation was observed after 6 h duration at 1 sun irradiation. Taking the advantages of the inherently adjustable chemical composition and tunable porosity of PIPs, the results of this work may open an opportunity for rational design and preparation of high-performance PIPs-based PM with desired salt-resistance for real SSG applications.