Multifunctional Perovskite Oxide for Efficient Solar-driven Evaporation and Energy-Saving Regeneration

Abstract Photothermal materials, which can realize the light-to-heat conversion, are the key factor to fast solar-driven evaporation for fresh water generation in desalination. In practical application, photothermal materials often meet the biological or organic contaminants, causing performance degradation or even invalidation. Pyrolysis is an ideal approach to contaminants decomposition for some thermostable materials, but still suffers high energy consumption. Here, a multi-functional cobalt-containing perovskite, La0.7Sr0.3CoO3, is developed for high-efficiency solar-driven evaporation and energy-saving regeneration in view of the good photothermal performance and activity in catalytic combustion. La0.7Sr0.3CoO3 slice with rationally designed surface and microstructure accelerates the evaporation up to 1.67 kg m-2 h-1, about 420% of natural water evaporation rate under 1.0-sun illumination. More importantly, La0.7Sr0.3CoO3 slice can catalyze the thermal decomposition of biological/organic contaminants like alga at a relatively lower temperature, meaning a lower energy consumption. Additionally, because of the superhydrophilic surface and porous structure for high accessibility of seawater, La0.7Sr0.3CoO3 slice can realize long-term salt rejection and ensure a stable performance on seawater evaporation which is meaningful in the practical solar-driven desalination.