Photothermal Interfacial Evaporation Characteristics of PVA/SA–CNT–Borax Hydrogel

ABSTRACT The desalination of seawater has demonstrated significant potential to use solar‐driven interfacial evaporation technologies due to its sustainability, outstanding productivity, and kindness to the environment. In this paper, a hydrogel interfacial evaporator was produced, with PVA and SA as the base materials. The addition of carbon nanotubes (CNTs) was used to enhance the photothermal conversion efficiency, and the cross‐linking procedure was carried out employing sodium tetraborate decahydrate (borax). The experimental study researched how evaporation efficiency was affected by varying sodium chloride concentrations, light intensity, and borax cross‐linking levels. The study confirmed that the hydrogel cross‐linked with 4% borax exhibits the best efficiency of evaporation, reaching a 2.709 kg/m 2 · h evaporation rate and 98% evaporation efficiency. Moreover, it demonstrates excellent salt tolerance and stability during the process. This study effectively created an inexpensive, eco‐friendly, nontoxic, and easy‐to‐fabricate hydrogel evaporator, which provides a very important reference value for the development of the novel kind of solar thermal evaporator.