Simultaneous evaporation and decontamination of water on a novel membrane under simulated solar light irradiation

Construction of semiconductor-based membranes accommodates new routes for photothermal conversion and in-situ decomposing of pollutants in solar light-driven evaporation. In this work, a novel photocatalyst composed of MoO3-x, BiOCl, and carbon nanotubes was surficial deposited on cellulose acetate membrane. High capillary pressure (∼600 kPa) guaranteed an effective capillary rise of water from hydrophilic membrane matrix. The water was extruded into ultra-fine droplets with a saturation vapor pressure as high as ∼1.75 × 105 Pa and a heat flux as much as ∼2.11 × 10−3 W mm−2. Moreover, the top-surficial film can harvest sufficient solar photons to generate charge carries, and the surface temperature of membrane can quickly increase to higher than 50 °C by thermalization through carriers relaxation, transference, and recombination on specific sites. Simultaneously, pollutants in water are efficiently decomposed by effectively separated charge carriers on designed spots. Synergistically, a steam generation rate of ∼7.75 kg m−2 h−1 was acquired and an almost complete removal of RhB and toluene was achieved.