Titania Composites with 2D Transition Metal Carbides as Photocatalysts for Hydrogen Production under Visible-Light Irradiation

MXenes, a family of two-dimensional transition-metal carbides, were successfully demonstrated as co-catalysts with rutile TiO sub(2) for visible-light-induced solar hydrogen production from water splitting. The physicochemical properties of Ti sub(3)C sub(2)T sub(x) MXene coupled with TiO sub(2) were investigated by a variety of characterization techniques. The effect of the Ti sub(3)C sub(2)T sub(x) loading on the photocatalytic performance of the TiO sub(2)/Ti sub(3)C sub(2 )T sub(x) composites was elucidated. With an optimized Ti sub(3)C sub(2)T sub(x) content of 5wt%, the TiO sub(2)/Ti sub(3)C sub(2 )T sub(x) composite shows a 400% enhancement in the photocatalytic hydrogen evolution reaction compared with that of pure rutile TiO sub(2). We also expanded our exploration to other MXenes (Nb sub(2)CT sub(x) and Ti sub(2)CT sub(x)) as co-catalysts coupled with TiO sub(2), and these materials also exhibited enhanced hydrogen production. These results manifest the generality of MXenes as effective co-catalysts for solar hydrogen production. Carbide composite co-catalyst: MXene (2D transition-metal carbide) co-catalysts are coupled with TiO sub(2) in composite materials to enhance visible-light-induced photocatalytic hydrogen production. The work provides insights into the photocatalytic mechanism of the composite, demonstrating that MXenes in general can be employed as effective co-catalysts to assist TiO sub(2) for solar hydrogen production.