Highly charged solar evaporator toward sustainable energy transition for in-situ freshwater & power generation

Hybrid solar-driven interfacial evaporation (HSDIE) systems are promising solar technologies for simultaneous freshwater and power generation. However, lower efficiencies due to inevitable heat losses, salt accumulation, and volatile organic impurities are detrimental to the sustainability of solar evaporators that limit their practical applications. Herein, we report a highly charged solar evaporator for in-situ freshwater and power generation developed by a UV-induced deposition of Fe3O4@PPy nanospheres anchored on a self-floating cellulose evaporator. The endowment of synergic resistance of ammonium (NH4+) ions is significantly increased by optimizing the positive charge density of R-NH+ groups by the Donnan exclusion without sacrificing the evaporation rates (1.98 kg m(-2)h(-1)) using Shahu Lake water/NH4Cl center dot H2O (25 wt%) slurry. The state-of-the-art investigations validate the long-term stability without any salt accumulation under natural conditions (mass change, 14.66 kg m(-2)/8 hrs). More importantly, in-situ thermoelectric power generation achieved power density (P-out similar to 45.4 Wm(-2), I-out similar to 101 mA) along with solar to electric conversion efficiency (gamma = 2.27 %) under 2 kW m(-2) solar irradiations. This work will further insight into further advancement in the multifunctional integration of solar evaporation technology concerning the water-energy nexus.

Automated summary

This study reports a highly efficient solar evaporator with improved evaporation rate and resistance to salt accumulation. The system is achieved by depositing Fe3O4@PPy nanospheres on a self-floating cellulose evaporator and optimizing the positive charge density of R-NH+ groups. It also demonstrates the capability to generate electricity from solar energy.