Synthesis of ultrathin, nano-sized Ti3C2Tx with abundant =O and –OH terminals and high transparency as a cocatalyst: Enabling design of high-performance Titania-Ti3C2Tx hybrid photocatalysts. (November 2022)

• Record Type: Journal Article
• Authors: Al Mayyahi, Ahmed; Sarker, Swagotom; M.Everhart, Brian; Tonyali, Bade; Yucel, Umut; B Amama, Placidus
• Is Part Of: Journal of physics and chemistry of solids. Volume 170(2022)
• Publication Date: 2022-11
• Subjects: Hybrid photocatalysts -- TiO2 -- MXene -- Cocatalyst -- Gas and liquid phase reactions; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2022.110875
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Conventional Ti3 C2 Tx used in photocatalysis usually has properties that are detrimental to the process such as thick layers, a micro-sized structure with low transparency, and a high concentration of fluorine terminals. Herein, we demonstrate the synthesis of ultrathin, nano-sized Ti3 C2 Tx with abundant oxygen-containing groups (=O and –OH) and high transparency (designated as N–Ti3 C2 Tx ) as an alternative cocatalyst in liquid and gas phase photocatalysis. N–Ti3 C2 Tx is prepared by a two-step process that involves etching Al from Ti3 AlC2 via fluorine treatment followed by simultaneous exfoliation and fluorine reduction. N–Ti3 C2 Tx is then coupled with TiO2 via hydration and dehydration approaches to form a photocatalyst (TiO2 –N–Ti3 C2 Tx ) with distinct morphology and surface chemistry. The small size of N–Ti3 C2 Tx facilitates a strong interfacial contact with TiO2, thereby enhancing electron transport between TiO2 and N–Ti3 C2 Tx, and electron-hole separation; and (2) the high transparency of N–Ti3 C2 Tx facilitates photon-TiO2 interactions. As a consequence, the photocatalytic activity of TiO2 –N–Ti3 C2 Tx is superior to that of pristine TiO2, TiO2 coupled with thin, micro-sized Ti3 C2 Tx that is characterized by low transparency and fluorine terminals, and the widely used Ti3 C2 Tx -based photocatalyst synthesized by thermal nucleation of TiO2 on Ti3 C2 Tx . The high photocatalytic activity of TiO2 –N–Ti3 C2 Tx is also attributed to the presence of abundant = O and –OH terminals on N–Ti3 C2 Tx that boosts pollutant adsorption. The study provides a rational approach for coupling TiO2 and Ti3 C2 Tx to promote beneficial charge transfer properties and synergistic effects that have far-reaching applications in photocatalysis. Graphical abstract: Image 1 Highlights: Synthesis of ultrathin, nanosized Ti3 C2 Tx (N–Ti3 C2 Tx ). N–Ti3 C2 Tx facilitates strong interfacial contact with TiO2 . N–Ti3 C2 Tx enables good interaction between photons and TiO2 . N–Ti3 C2 Tx is terminated by = O and –OH groups for effective pollutant adsorption. TiO2 –N–Ti3 C2 Tx hybrid exhibits high photocatalytic activity in liquid and gas phases.