Wormlike Perovskite Oxide Coupled with Phase-Change Material for All-Weather Solar Evaporation and Thermal Storage Applications

Abstract

Interfacial solar-driven water evaporation has shown promising prospects in desalination technology. However, the lower photothermal conversion efficiency caused by the intermittent nature of sunlight and salt accumulation remains a significant challenge for continuous desalination. Herein, the hierarchical design of interfacial solar evaporation is reported, which realizes enhanced photothermal conversion, waste heat storage/release, and effective thermal management for continuous desalination. The solar evaporator is composed of worm-like SrCoO3 perovskite oxide anchored on super hydrophilic polyurethane (PU) foam succeeded by in situ polymerization of conducting polypyrrole (SrCoO3@PPy). The energy storage system is introduced within polyurethane matrix by a paraffin block followed by a tongue-and-groove structure for convective water transportation, and a heat recovery unit largely reduces heat losses. The solar evaporator possesses excellent evaporation rates (2.13 kg m−2 h−1) along with 93% solar-to-vapor conversion efficiency under 1 kw m−2 solar irradiation owing to its minimum equivalent evaporation enthalpy and (0.85 kg m−2 h−1) under intermittent solar irradiation as compared to conventional solar evaporators. More importantly, state-of-the-art experimental investigations validate waste heat recovery/release and the salt-resistant capability of solar evaporators optimized by computational fluid dynamic simulation. This study breaks conventional solar interfacial evaporation's limitations and demonstrates stable desalination under intermittent sunlight.