Multilevel nanochannels for high-efficient ion selectivity and salinity gradient power generation
Salinity gradient energy is widely present in river estuaries and has a huge reserve.Salinity gradient energy can be directly transformed into electrical energy via reverse electrodialysis,which has recently garnered widespread attention due to its simple and pollution-free utilization process.The emergence of two-dimensional(2D)materials has brought new opportunities because regular nanochannels and abundant functional groups enable their output power density to exceed the commercial standard of 5 W m-2.However,the membrane testing area for salinity gradient power generation is generally 3 × 104 μm2,and the power decreases considerably with increasing testing area.In this paper,a 2D-2D multilevel layered structure of graphene oxide and molybdenum disulfide(GO-MoS2)is prepared using a simple vacuum filtration method.This structure enables the ion-selective membrane to maintain an ordered structure even over a large area,achieving high ion selectivity and transport and eventually reaching high output power density.Meanwhile,the prepared 2D-2D structure effectively controls swelling in 2D material membranes and offers abundant surface holes and multilevel interlayer spacing,thereby realizing fast ion-selective transport.The osmotic power generation test results over a large area(3.14 mm2,100 times larger than those of other studies)showed that the osmotic voltage and current of the GO-MoS2 membranes perform satisfactorily,with a power density of 0.57 W m-2 at a 100-fold gradient,which is 92.7％higher than those of the original GO membranes.The 2D-2D multilevel layered structure provides a new perspective for fabricating large-area and simple-to-prepare high-performance ion-selective membranes and guidance for the industrial application of 2D materials in the fields of salinity gradient power generation,seawater desalination,gas separation,biomedicine,and so on.
salinity gradient power generationreverse electrodialysisgraphene oxidetwo-dimensional materials
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维普
