A Janus and superhydrophilic design for stable and efficient high-salinity brine solar interfacial desalination

Abstract

Solar interfacial desalination is a potential pathway for freshwater using solar energy and brine. Many recent advances have been extensively studied to high-efficiency solar steam yield, however, the decrease of evaporation performance resulted from salt accumulation at absorbers inevitably hinder their development, especially in high-salinity brine (>10 wt%). Here, we propose a Janus and superhydrophilic designed evaporator for efficient and stable solar interfacial desalination in high-salinity brine. The Janus structure of the absorber, which has an upper layer of very light-absorbing (>95 %) carbon fiber powder and a bottom layer of insulated aramid fiber powder, allows for efficient light absorption and thermal management to promote efficient water evaporation. Furthermore, the impact of carboxylate cellulose ensures that the absorber with an ultra-high-water content and salt ion diffusion rate. Therefore, the Janus and superhydrophilic design can realize an evaporation rate as high as 1.25 kg m−2h−1 with a salinity of 15 wt% brine under 1-sun illumination and achieve salt resistance in outdoor conditions for a long time. Therefore, this technique simply integrates outdated fiber powder with the current solar interfacial evaporators and establishes a new paradigm for very effective and reliable high-salinity brine treatment.