Simultaneous Delamination and Rutile Formation on the Surface of Ti3 C2 Tx MXene for Copper Adsorption

Abstract

In this work, we studied the formation of the rutile phase of titanium dioxide (TiO₂ ) on delaminated MXene (d-Ti₃ C₂ T_x ) flakes by the reaction of Ti₃ C₂ T_x with amino acids in water. Three types of amino acids with varied side-chain polarity were used to delaminate Ti₃ C₂ T_x . d-Ti₃ C₂ T_x flakes formed stable colloidal solutions due to the negative surface charges of chemisorbed amino acids on the d-Ti₃ C₂ T_x . Rutile formed on d-Ti₃ C₂ T_x at room temperature upon the intercalation of aromatic amino acids and subsequent sonication of the solution, while flakes intercalated with aliphatic amino acids did not oxidize. X-Ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy revealed the nanosize rutile formation on the surface of Ti₃ C₂ T_x flakes. The XPS results indicated the surface functionalization of histidine on d-Ti₃ C₂ T_x flakes. As-synthesized histidine functionalized rutile TiO₂ @d-Ti₃ C₂ T_x hybrid was used for adsorption of Cu²⁺ ions from aqueous solution with a maximum uptake of 95 mg g^-1 .

Keywords: Adsorption; Amino acids; Copper; MXene-Ti3C2Tx; Titanium dioxide.