Perovskite structured LaCoO3 photothermal material decorated nanocellulose aerogel for efficient interfacial solar steam generation

• The bilayer structure is designed by CNF aerogel coated with LaCoO 3 . • AG-LCO evaporator achieves an evaporation rate of 1.904 kg m -2 h⁻¹ under 1 kW m - ². • AG- LCO evaporator exhibits the excellent stability and reusability. Interfacial solar steam generation offers an innovative solution to address freshwater scarcity. However, constructing a durable, cost-effective and efficient solar evaporator with high salt resistance still remains a challenge. In this study, aerogel is fabricated by lyophilization of the hydrogels, made of cellulose nanofibrils (CNFs) crosslinked with epichlorohydrin (ECH). The top surface of the aerogel is then coated with multifunctional perovskite photothermal material to form three-dimensional bilayer aerogel evaporator. Here, perovskite structured sodium tantalum oxide (NTO) and lanthanum cobaltite (LCO) are used as photothermal material. From the experimentation, aerogel coated with LCO (AG- LCO) evaporator achieves a high evaporation rate of 1.904 kg m -2 h⁻¹ under 1 kW m - ² light intensity due to the impressive optical properties and narrow bandgap of LCO in addition to rapid diffusion of water and capillary action. AG- LCO evaporator has the ability to remove salt from higher concentration solution (26 wt% NaCl solution) with the evaporation rate of 1.473 kg m −2 h −1 and reduce the concentration of ions in seawater. Further, this evaporator has the ability to remove dye molecule from aqueous solution of methylene blue and sulphone black. The outcome of the evaporator offers the potential for the practical application of dye removal, waste water treatment and seawater desalination.