Photothermal-photocatalytic route of MOF-based membrane with nanosheet array structures for solar-driven water purification

Solar-driven interfacial evaporation technology is a promising sustainable approach to mitigate the global energy crisis and clean water scarcity. The advanced interfacial evaporation materials make a non-negligible contribution to the solar thermal utilization for water purification. In this work, a Cu-catecholate metal–organic framework-based photothermal membrane (Cu-CATM) is developed to generate freshwater from seawater and recover clean water from wastewater. Thanks to the unique photothermal effect and the three-dimensional nanosheet array structure of Cu-catecholate metal–organic framework (Cu-CAT MOF), the Cu-CATM enabled a promising evaporation rate of 2.43 kg m−2h−1 and a high solar-vapor conversion efficiency of 92% under solar irradiance of 1 sun. Further, the Cu-CATM could be applied to solar seawater desalination with durable evaporation rate and no salt accumulation. Also, the Cu-CATM enabled solar utilization for synchronous photothermal desalination and photocatalytic degradation, which highlighted the broader environmental application for water remediation or wastewater treatment via photothermal-photocatalytic route. This work presents a viable and effective route for the development of photothermal membranes toward future sustainable clean water production from non-conventional water resources.