Carbon nanofibers membrane bridged with graphene nanosheet and hyperbranched polymer for high-performance osmotic energy harvesting

Reverse electrodialysis(RED),based on ion-selective membranes,is one of the most promising technologies for capturing osmotic energy.As key elements of the RED system,ion-selective membranes must meet the crucial demands of mechanical stability,anti-fouling characteristics,easy fabrication,and high power density;however,this still remains a challenge.In this study,we demonstrated a large-scale,mechanically stable,and high-porosity membrane obtained by combining carbon nanomaterials and hyperbranched polyethyleneimine(h-PEI),thereby achieving a high power density of 5.0 W·m−2 with seawater and river water.Carbon nanofibers(CNFs)were subsequently bridged with graphene and h-PEI to strengthen the interaction between the CNFs,reduce the channel size and increase the space charge density,mechanical strength,and toughness.The large-scale and mechanically stable membrane fabricated using the modified CNFs exhibited anion selectivity and high ionic conductivity,thereby achieving a high-performance osmotic energy conversion.Furthermore,the anti-fouling property of the membrane was confirmed by the stability of the osmotic energy conversion in a solution with algae,which can be attributed to the high porosity of carbon nanomaterials.This economic and convenient method for the ion-selective membrane preparation is believed to be promising for large-scale osmotic energy harvesting.

Construction and application of bioinspired nanochannels based on two-dimensional materials

With the development of nanotechnology and materials science,bioinspired nanochannels appeared by mimicking the intelligent functions of biological ion channels.They have attracted a great deal of at-tention in recent years due to their controllable structure and tunable chemical properties.Inspired by the layered microstructure of nacre,2D layered materials as excellent matrix material of nanochannel come into our field of vision.Bionic nanochannels based on 2D materials have the advantages of facile preparation,tunable channel size and length,easy expansion,and modification,etc.Therefore,the 2D layered nanofluid system based on bionic nanochannels from 2D layered materials has great potential in biomimetic microsensors,membrane separations,energy conversion,and so on.In this paper,we focus on the construction and application of bionic nanochannels based on 2D layer materials.First,a basic understanding of nanochannels based on 2D materials is briefly introduced,we also present the property of the 2D materials and construction strategies of bionic nanochannels.Subsequently,the application of these nanochannels in responsive channels and energy conversion is discussed.The unsolved challenges and prospects of 2D materials-based nanochannels are proposed in the end.