Solvothermal-induced assembly of 2D-2D rGO-TiO₂ nanocomposite for the construction of nanochannel membrane

A solvothermal-induced assembly of a 2D-2D reduced graphene oxide (rGO)-TiO₂ mesoporous material with a laminar structure for membrane construction is reported, in which using 2D-2D rGO-TiO₂ as building blocks can preeminently enhance the separation properties of the as-prepared membrane without sacrificing the permeance. Taking advantage of the large specific surface area (324 m²/g) available for interfacial effects as well as interwoven stacking and narrow layer spacing of 2D morphologies for size exclusion, the fresh rGO-TiO₂ membrane exhibited excellent separation performance toward organic dye from water (>97.3% for Rhodamine B, Methyl orange, Methyl blue and Congo red), while achieving good permeance up to approximately 9.36 L m⁻² h⁻¹ bar⁻¹ and an outstanding structural stability under the cross-flow process of filtration. More importantly, the reduced band gap energy (Eg) of 2D-2D rGO-TiO₂ membrane layer (2.77 eV) compared with that of the blank TiO₂ membrane (3.24 eV) allows the rGO-TiO₂ membrane to have an impressive self-cleaning ability and thus exhibits great potential application in the field of membrane separation.