A solar-electric dual-driven microporous hydrogel evaporator for all-weather highly efficient water purification

Abstract

Solar-driven interfacial water evaporation technology holds significant potential for addressing global water scarcity. However, the variable nature of solar intensity in natural environments limits its reliability for all-weather highly efficient water purification. Herein, we develop a novel solar-electric dual-driven water purification evaporator featuring an electrically heated mesh within a microporous hydrogel composed of carbon nanotubes (CNTs) and polyacrylamide (PAAm). The synergistic photothermal and electrothermal effect of the microporous hydrogel enables the dual-driven evaporator to achieve an ultrafast evaporation rate of 16.35 kg m−2 h−1 under one sun irradiation with 3 A current input, demonstrating remarkable superiority to other dual-driven evaporators. Even under dark conditions, the evaporator maintains robust performance, achieving an impressive evaporation rate of 6.45 kg m−2 h−1, which surpasses existing photothermal-driven systems. Significantly, the integration of the solar-electric dual-driven evaporator with solar panels and a mobile power source creates a water purification system that can achieve closed-loop solar energy utilization. A five consecutive rainy day outdoor validation demonstrates that such a system exhibits an excellent average water collection rate of 3.1 kg m−2 d−1. This work provides a convenient and efficient approach to enhance the accessibility of purified water under varying environmental conditions.