A stable all-day interfacial evaporation multistage distillation driven by solar photothermal and solar electrothermal

Abstract

Solar-powered interface vapor generation offers a promising approach to sustainable desalination. However, the diurnal nature of solar energy leaves evaporators idles for nearly half their lifetime. Existing evaporators that set electricity as an auxiliary energy source for nighttime evaporators have a series of electrochemical problems, such as short circuits, corrosion, and water electrolysis, making it difficult to achieve continuous and stable freshwater production. Here, we designed solar absorbers by modifying carbon black (CB) on the far-infrared radiation paper (FIRP) surface for simultaneous photothermal conversion and joule heating. The absorber is further set in a multistage distillation (MSD) device for interfacial evaporation and latent heat recovery. The MSD device is designed with mutually insulated circuitry and water transfer paths to avoid electrochemical reactions within the device fundamentally. As a result, the MSD device achieved evaporation rates of 2.2 and 2.5 kg m-2h−1 at 1 kW m−2 solar-driven and electric-driven inputs, respectively. In particular, the MSD device achieved a continuous and stable operation of 240 h under alternating solar and electric drive. This method provides a new idea for the long-term continuous operation of interfacial evaporators.