Oil/water separation and functionality of smart carbon nanotube–titania nanotube composite

Abstract Water treatment applications are in high demand recently. In this work, the titania nanotube (TNT) was successfully grown onto the outer surface of the carbon nanotubes (CNTs) via the hydrothermal method. The resultant prepared composite was doped with different ratios of nitrogen. The structural and morphological merits of the composites displayed the successful composition of the matrices, as well as the particle size of the composite within the nanoscale. The optical specifications of the composites demonstrate successful direct and indirect transitions with a high energy gap (> 3 eV). The testing of different oils in the water/oil separation exhibited a high rate of success to split oil and water (> 95%). In this regard, CNT-TNT 1.0 sample reflects the highest efficiency. Compared to other researchers that demonstrate the highest efficiency of their proposed structure, our membrane offers a decent separation efficiency. The proposed composite might provide a feasible and cost-effective method for water/oil separation application in the nanotechnological fields. Graphical abstract