Noncovalent functionalization of TiCT using cationic porphyrins with enhanced stability against oxidation

• Published in: Materials chemistry frontiers Vol. 6; no. 5; pp. 561 - 569
• Main Authors: Thurakkal, Shameel, Zhang, Xiaoyan
• Format: Journal Article
• Published: 28.02.2022
• ISSN: 2052-1537
• DOI: 10.1039/d1qm01326b

Ti 3 C 2 T X , as the most explored MXenes, are a rising star among 2D materials due to their astonishing physicochemical properties. However, their practical applications remain extremely challenging because of chemical degradation into TiO 2 nanoparticles due to oxidation. Chemical functionalization is an effective way to improve their stability against oxidation and tune the physicochemical properties of 2D materials. In this paper, Ti 3 C 2 T X is noncovalently functionalized using two different cationic porphyrins and the two hybrids show good stabilities in water against oxidation. The electrostatic interactions between the cationic porphyrins and the Ti 3 C 2 T X nanosheets are confirmed by the changes in the zetapotential and the photophysical measurements. The hybrids show a red shifted Soret band of the porphyrins with a complete quenching of the fluorescence emission, which confirms the effective interactions and an energy/electron transfer between the porphyrins and the Ti 3 C 2 T X nanosheets. The exfoliated and functionalized Ti 3 C 2 T X are characterized using various microscopic and spectroscopic techniques. The two hybrids exhibit pH dependent release of cationic porphyrins particularly under acidic conditions. This study proposes a potentially useful strategy for the preparation of highly stable and functional MXenes towards promising applications in biomedicines, optoelectronics and sensors. Noncovalently functionalized Ti 3 C 2 T X MXenes are prepared via electrostatic interactions between cationic porphyrins and Ti 3 C 2 T X . Various spectroscopic and microscopic techniques are used to characterize the two hybrids, which show enhanced stability against oxidation and a pH dependent release of the porphyrins.