ABSTRACT
Membrane separation is recognized as one of the most effective strategies to treat the complicated wastewater system for economic development. However, serious membrane fouling has restricted its further application. Inspired by sphagnum, a 0D/2D heterojunction composite membrane is engineered by depositing graphitic carbon nitride nano/microspheres (CNMS) with plentiful wrinkles onto the polyacrylic acid functionalized carbon nanotubes (CNTs-PAA) membrane through hydrogen bond force. Through coupling unique structure and chemistry properties, the CNTs-PAA/CNMS heterojunction membrane presents superhydrophilicity and underwater superoleophobicity. Furthermore, thanks to the J-type aggregates during the solvothermal process, it is provided with a smaller bandgap (1.77 eV) than the traditional graphitic carbon nitride (g-C3 N4 ) sheets-based membranes (2.4-2.8 eV). This feature endows the CNTs-PAA/CNMS membrane with superior visible-light-driven self-cleaning ability, which can maintain its excellent emulsion separation (with a maximum flux of 5557 ± 331 L m-2 h-1 bar-1 and an efficiency of 98.5 ± 0.6%), photocatalytic degradation (with an efficiency of 99.7 ± 0.2%), and antibacterial (with an efficiency of ≈100%) ability even after cyclic experimental processes. The excellent self-cleaning performance of this all-in-one membrane represents its potential value for water purification.
Subject(s)
Nanotubes, Carbon , Sphagnopsida , Water Purification , Microspheres , SunlightABSTRACT
A surge of effort has been devoted to establishing super-wetting membranes with versatility for oily waste water purification. However, persistent challenge remains the lower separation flux. Moreover, the majorities of catalysts are only adsorbed on the surface and easily fall off after multiple cyclic separations. In this work, an effective strategy has been taken to construct a composite membrane consisting of polyacrylic acid functionalized carbon nanotubes (CNTs-PAA) and MIL101(Fe)@platinum nanoparticles (MIL101(Fe)@Pt NPs). The obtained CNTs-PAA/MIL101(Fe)@Pt composite membrane can achieve degradation of dye molecules and at the same time effective separation of oil-in-water emulsions. The separation throughput of this composite membrane can reach up to 11000 L m-2 h-1 bar-1, which has exceeded most of the previous reported multifunctional separation membranes. Furthermore, this composite membrane has presented stable mechanical property and excellent anti-corrosion ability. This work gives comprehensive consideration to excellent separation performance, versatility and stability, which could have potential applications in practical oily wastewater treatment.
