In-Situ Fabricating V 2 O 5 /TiO 2 -Carbon Heterojunction from Ti 3 C 2 MXene as Highly Active Visible-Light Photocatalyst.

Titanium dioxide is a mainstream photocatalyst, but it still confronts great obstacles of poor visible light absorption and rapid recombination rate of photogenerated carriers. Herein, we describe the design of a highly active visible-light photocatalytic system of graphited carbon layers anchored V 2 O 5 /TiO 2 heterojunctions derived from Ti 3 C 2 MXene, which demonstrates about 4.58 and 2.79 times higher degradation activity of MB under visible light (λ > 420 nm) than pure V 2 O 5 and TiO 2 -carbon. Combined with the characterization results, the formed V 2 O 5 /TiO 2 heterojunction promotes the separation of photogenerated carriers, while the graphitized carbon derived from MXene acts as an electronic reservoir to enhance the absorption of visible light. The ESR results show that superoxide radicals and hydroxyl radicals are the main active species in the reaction system. Therefore, we propose a possible mechanism model to provide a feasible idea for the subsequent design of high-efficiency photocatalysts for environmental treatment.