A Self‐Cleaning Heterostructured Membrane for Efficient Oil‐in‐Water Emulsion Separation with Stable Flux

Abstract

Lack of clean water is a major global challenge. Membrane separation technology is an ideal choice for the treatment of industrial, domestic sewage owing to its low energy consumption and cost. However, membranes are highly susceptible to contamination, particularly during wastewater treatment, which has limited their practical applications in this field. Similarly, the flux of the membrane decreases with prolonged use due to its reduced interlayer spacing. Preparation of membranes with anticontamination properties and stable flux is the key to addressing this problem. In this study, a 2D heterostructure membrane with visible‐light‐driven self‐cleaning performance is prepared via a self‐assembly process. Notably, the addition of palygorskite increases the interlayer spacing of the graphene and heterojunction structures, which increases the flux of the membrane and avoids a decrease of the interlayer spacing of the membrane under pressure. The presence of a heterojunction with visible light catalytic properties effectively avoids membrane fouling and avoids a sharp decrease of the permeation flux. Importantly, the prepared 2D membrane has excellent separation performance for oil–water emulsions with both high flux and efficiency. These features suggest great potential for the prepared 2D membrane in wastewater treatment applications.

Engineered partially open-cage fluorinated polyhedral oligomeric silsesquioxane hybrid nanoparticle aggregates for surfaces with super-repellency to widespread liquids

“…10 In the engineering design and fabrication of super-repellent surfaces, the two-in-one function of low surface energy species-decorated microparticles or nanoparticles is also of great use to avoid the weak compatibility of polymer resins with free low surface energy chemicals. 8 Regardless of whether they are high and low surface tension liquids, high and low viscosity liquids, or Newtonian and non-Newtonian liquids, if the widespread liquids have an ultralow adhesion to the surfaces and effortlessly roll off, this indicates that such superrepellent surfaces are more efficiently applicable to practical elds, such as self-cleaning/anti-fouling, 11,12 anti-icing, 13,14 antibacteria, 15,16 corrosion protection, 17,18 energy-efficient uid transport, 19,20 water-oil separation 21,22 et al In this case, the microparticles or nanoparticles with ultralow surface energy are necessary to impart the surfaces with super-repellency to widespread liquids. Fluorinated polyhedral oligomeric silsesquioxane (FPOSS), consisting of a silicon-oxygen (Si-O) inorganic core (cage-like structure) and a uoroalkyl chain (controlled chain length of -CF 3 /-CF 2 ) organic periphery or shell, 23,24 has the lowest surface energy (g s ¼ 9.3 mN m À1 ) in articially synthesized molecules, 25,26 and is proved to be chemically stable.…”

Synergetic Advantages of Atomically Coupled 2D Inorganic and Graphene Nanosheets as Versatile Building Blocks for Diverse Functional Nanohybrids

“…[98] For instance, a 2D heterostructure membrane was fabricated from GO, g-C 3 N 4 @Bi 2 O 2 CO 3 , and palygorskite for application in wastewater treatment. [99] Upon the formation of palygorskite and g-C 3 N 4 @Bi 2 O 2 CO 3 heterojunction, this membrane boasted a greatly enhanced water flux compared to the pure GO membrane. This superoleophobic membrane was found to exhibit a stable flow rate after multiple cycles, in addition to excellent self-cleaning properties (flux recovery rate >95%) for oil-in-water emulsions.…”

Recyclable Ag/TiO2@PDMS Coated Cotton Fabric with Visible-Light Photocatalytic for Efficient Water Purification

“…The pollutants attached to the surface of the separation materials have been effectively degraded by visible light catalytic degradation of the composite materials prepared in this study, and the recycling of the materials has been realized. No obvious residues remained on the surfaces of the Ag-TiO 2 @PDMS coated cotton fabric, indicating that the Ag-TiO 2 @PDMS coated cotton fabric exhibited excellent anti-pollution properties (Cai et al 2020;Tang et al 2021).…”