Engineering of porous graphene oxide membranes for solar steam generation with improved efficiency

Abstract

Interfacial solar steam generation (ISSG) is considered to be a highly efficient and environmentally friendly desalination technique for producing potable water. Herein, we demonstrate high-performance SSG enabled by a porous graphene oxide (named P-GO) membrane which is prepared by a facile etching method. The results show that the solar absorptivity of the P-GO membrane is more than 85% which is much higher than that of a pure GO membrane (∼75%). This is attributed to the enhanced internal reflection of incident light between GO layers within the porous structure. As a result, the evaporation rate and the evaporation efficiency of the P-GO membrane reach 1.77 kg m⁻² h⁻¹ and 88.26% under 1 kW m⁻² irradiation. Moreover, the salt removal performance of the P-GO membrane is verified in natural lake water. Meanwhile, organic pollutants, such as methylene blue, can also be effectively captured from sewage water (removal rate reaches 99.13%). Thus, the P-GO membrane is thought to be a promising candidate for high efficiency ISSG in water purification and seawater desalination.