MXene-motivated accelerated charge transfer over TMCs quantum dots for solar-powered photoreduction catalysis.

[Display omitted] • Transition metal chalcogenides/MXene heterostructures were judiciously designed by a ligand-triggered self-assembly strategy. • Ti 3 C 2 T x (MXene) can serve as an efficient interfacial charge transfer mediator to prolong charge lifetime. • Multifarious photoreduction catalysis has been comprehensively probed. • The role of Ti 3 C 2 T x (MXene) as charge mediator has been evidenced to be universal. Transition metal chalcogenides quantum dots (TMCs QDs) demonstrate emerging potential in solar energy conversion owing to marvelous physicochemical properties, such as quantum size effect, large extinction coefficient, and multiple excitons generation. Nevertheless, TMCs QDs as photosensitizers are unstable owing to high surface energy, and moreover, substantial trap states of TMCs QDs annihilate the photo-induced charge carriers, thus resulting in ultra-short charge lifetime and inferior photoactivities. Herein, 0D/2D TMCs QDs/MXene heterostructures were designed by a ligand-initiated electrostatic self-assembly strategy, wherein positively charged TMCs QDs were anchored on the negatively charged ultrathin Ti 3 C 2 T x nanosheets (NSs) framework, which promotes the anisotropic unidirectional electron transport from TMCs QDs to MXene NSs. MXene functions as an effective charge mediator to decrease the charge recombination and prolong the charge lifetime for photocatalytic hydrogen generation and anaerobic reduction of nitroaromatics to amino compounds under visible light irradiation. Our work would shed new insights on the role of MXene in tuning the directional charge transport for solar energy conversion. [ABSTRACT FROM AUTHOR]