MXene nanosheets functionalized with Cu atoms for urea adsorption in aqueous media

• Main Authors: Yen, Zhihao, Salim, Teddy, Boothroyd, Chris, Haywood, Peter Ferdinand, Kuo, Cheng-Tai, Lee, Sang-Jun, Lee, Jun-Sik, Cho, Deok-Yong, Lam, Yeng Ming
• Other Authors: Facility for Analysis, Characterisation, Testing and Simulation (FACTS)
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Materials::Composite materials; Two Dimensional Materials; Ti3C2Tx MXene; Urea Adsorption; Functionalization; Single Atom
• Online Access: https://hdl.handle.net/10356/170896
• Institution: Nanyang Technological University

Ti3C2Tx MXene is an emerging family of two-dimensional materials, and because of its large specific surface area, it has potential for many applications. Herein, a new application using Cu-doped MILD (minimally intensive layer delamination) synthesized Ti3C2Tx MXene for urea removal is demonstrated. The doping of Cu on MXene results in an increase in its affinity for urea adsorption as compared to the pristine MILD synthesized MXene due to the formation of the Cu−urea complex. Previous computational studies have shown that the adsorption energies of urea on the MXene surface can be improved in the presence of Cu. The valence state of Cu in the doped MILD synthesized MXene, which binds on to the surface via Ti−O−Cu linkage, is between 0 and +1 as verified by XAS and XPS. As the optimal urea adsorption occurs on Cu as a single atom site, an increase in Cu doping on MXene does not increase urea removal due to Cu agglomeration. Looking at the adsorption behaviour, it seems that Cu-doped MXene follows the monolayer adsorption on homogenous surface model.