All in one doubly pillared MXene membrane for excellent oil/water separation,pollutant removal,and anti-fouling performance

Given the diversity and complexity of coexisting oil/dyes/heavy metal ions/microorganisms in wastewater and volatile organic compounds(VOCs)in the air,developing separation materials featured in higher separation efficiency and lower energy consumption for oil and water separation,pollutant removal,and anti-fouling is urgently needed,but it remains a major challenge till now.Herein,a multifunctional Ti3C2 MXene membrane with unique double pillar support was proposed by liquid phase ultrasonication and vacuum filtration to over-come the above challenge.Introducing cetyl-trimethyl ammonium bromide(CTAB)and calcium chloride/sodium alginate(CaCl2/SA)to the MXene membrane as crossed double pillars and superhydrophilic surface increases the tolerance and wettability of the membrane.The fabricated doubly pillared MXene(d-Ti3C2)membrane exhibits superior oil/water(O/W)separation efficiency(99.76％)with flux(1.284 L m-2 h-1)for canola oil and organic dye removing efficiency for methyl blue(MB)99.85％,malachite green(MG)100％,and methyl violet(MV)99.72％,respectively,which is 1.05,1.44,1.22,and 1.28 fold compared with pre-pillared Ti3C2(p-Ti3C2).The superior anti-oil/dye/fouling is attributed to lower oil conglutination,high hydrophily,and antibacterial activity.The versatile MXene membrane also shows distinguished separation of VOCs(η＞99％)from polluted air.The experimental and molecular dynamics(MD)computational simulation results illustrate that the superior sepa-ration efficiency of the Ti3C2 MXene membrane is ascribed to the unique doubly pillared space channel.This study paves a new road to further research on one step integration strategy for complex O/W separation,wastewater and VOCs removal,and anti-fouling via tuning nano/macro architecture.