Enhanced charge transfer for efficient photocatalytic H2 evolution over UiO-66-NH2 with annealed Ti3C2Tx MXenes

The annealed Ti3C2Tx MXenes retained original layered morphology and gave rise to the formation of TiO2 is anticipated to achieve improved photocatalytic hydrogen evolution performance as a noble-metal-free co-catalyst. In this work, a novel Ti3C2/TiO2/UiO-66-NH2 hybrid was rationally designed for the first time by simply introducing annealed Ti3C2Tx MXenes over water-stable Zr-MOFs (UiO-66-NH2) precursors via a facile hydrothermal process. As expected, the rationally designed Ti3C2/TiO2/UiO-66-NH2 displayed significantly improvement in photocatalytic H-2 performance (1980 mu mol.h(-1).g(-2)) than pristine UiO-66-NH2 under simulated sunlight irradiation. The excellent photocatalytic HER activity can be attributed to the formation of multi-interfaces in Ti3C2/TiO2/UiO-66-NH2, including Ti3C2/TiO2/UiO-66-NH2, Ti3C2/TiO2 and Ti3C2/TiO2/UiO-66-NH2 interfaces, which constructed multiple pathways at the interfaces with Schottky junctions to accelerate the separation and transfer of charge carriers and endowed the accumulation of photo-generated electrons on the surface of Ti3C2. This work expanded the possibility of porous MOFs for the development of efficient photocatalytic water splitting using annealed MXenes. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.