Multilayered Co-Fc MOF/GO 3D evaporator for efficient solar-driven water generation and wastewater purification

Abstract

Solar-driven interfacial water evaporation (SDIWE) technology is an promising way to solve the shortage of fresh water scarcity. However, it is still challenging to generate clean water from organic compound contaminated water through SDIWE. Herein, a 3D multilayer inverted cone solar evaporator based on flexible MOF/graphene oxide composite membrane (CFG membrane) is designed for efficient water evaporation and purification. The Co-Ferrocene (Co-Fc) MOF loaded in the CFG membrane expands the interlayer spacing of GO, providing channels for water transport and enhancing the photothermal performance. The 3D multilayer inverted cone structure enhances the absorption of sunlight through multiple reflections of light between different layers. Based on the above design, the 3D evaporator with three layer CFG membranes demonstrates an evaporation rate of 2.28 kg m-2 h-1 under 1-sun illumination, good salt-resistance and long-term stability. Meanwhile, the Co-Fc MOF in the evaporator acts as an effective Fenton catalyst and promote the generation of ˙OH for the degradation of organic pollutants in wastewater. The degradation rate of pollutants in mixed wastewater (MB: 80 mg L-1; TC: 40 mg L-1; phenol: 40 mg L-1) by CFG-3 evaporator is all over 95%. Almost no volatile organic compounds (VOCs) were detected in the distilled water. This may provide a promising strategy for the efficient solar-driven evaporation and treatment of organic wastewater.