Recent advances in partially and completely derived 2D Ti3C2 MXene based TiO2 nanocomposites towards photocatalytic applications: A review

A large amount of research nowadays focuses on a new class of promising Ti3C2 MXenes analogous to conventional graphene. Ti3C2 MXene has specifically emerged as a two-dimensional (2D) layer structured material that successfully exfoliated from the Ti3AlC2 MAX phase. This review mainly emphasizes the optimized experimental conditions that explore promising partially (Ti3C2/TiO2) and completely derived (carbon-supported TiO2-(TiO2@C)) Ti3C2 MXenes. Accordingly, Ti3C2/TiO2 and TiO2@C nanocomposites highlighted superior photocatalytic dye degradation and hydrogen (H2) production compared to their base components under UV and visible light conditions. Apart from sustainable H2 generation, Ti3C2/TiO2 composite accomplished the versatile photocatalytic MO-, RhB-, MB-dye degradation, CO2 reduction, N2 photofixation, antiepileptic carbamazepine (CBZ) drug degradation, benzyl alcohol to aldehydes and bisphenol A (BPA). More importantly, prominent TiO2 nanostructures (nanoparticles, nanosheets, nanocrystals, nanorods etc.) were uniformly derived on Ti3C2, which induced intimate interaction at the interface and intended to create multiple heterojunctions. As a result, integration of optically active TiO2 and electrically conductive Ti3C2 offered superior charge carrier generation, separation, and reduced recombination rate under constructive Schottky junction formation at the interface of Ti3C2/TiO2. Considering the above promising features, we comprehensively summarized the superior photocatalytic performance of Ti3C2/TiO2, TiO2@C, and its composites. Moreover, the role of surface functional groups (–OH, –O and –F) developed on Ti3C2/TiO2 is explored. Finally, challenges faced are discussed and future perspectives also presented.