Catalysis-involved 3D N-doped graphene aerogel achieves a superior solar water purification rate and efficiency

Solar-driven water evaporation is a promising technology to address the water scarcity concern. While in the past years this research direction has initiated sizable progress in water purification, its application remains chal-lenging due to the low water evaporation rate and treatment efficiency. Herein, a 3D cylinder evaporator (SMNG) with superior evaporation rate and excellent water treatment efficiency is developed through a unique 3D structural design by incorporating catalytic Ag-MnO2 nanostructure with N-doped graphene aerogel. The SMNG evaporator possesses an evaporation rate as high as 6.46 kg m- 2 h-1 under one sun irradiation, with a photothermal conversion efficiency of 90.25 %. In addition, the SMNG also exhibits a remarkable desalination ability, with an evaporation rate of 6.15 kg m- 2 h-1 and an ions rejection rate up to 99.9 % on seawater. In an outdoor environment, the SMNG can attain a maximum seawater evaporation rate of 8.57 kg m-2 h-1, demonstrating its promising practical applications. The SMNG evaporator also shows over 99.9 % efficiencies in purifying wastewater that contains organic dyes, heavy ions, formaldehyde, and E. coli.

Automated summary

In this study, a 3D cylinder evaporator with superior evaporation rate and excellent water treatment efficiency was developed through a unique 3D structural design. The evaporator shows high evaporation rate and photothermal conversion efficiency under sunlight, and exhibits remarkable desalination ability and wastewater purification efficiency. This research has significant practical applications.