The first luminescent two-dimensional MOF nanosheets NTU-9-NS Ti2(HDOBDC)2(H2DOBDC) (H2DOBDC=2,5dihydroxyterephthalic acid) fabricated via top-down delamination have been realized for fast-response and highly sensitive sensing of Fe 3+ . The highly dispersive nature and high accessible active sites on the surface of the 2D NTU-9-NS nanosheets enable them to have close contact with targeted metal ions, which led to fast-response and highly sensitive sensing of Fe 3+ ions, with the response time within seconds and the best detection limit performance of 0.45 µM among MOF materials. The fast-response and highly sensitive Fe 3+ sensing based on the NTU-9-NS nanosheets sensor material highlights the very promise of luminescent sensing applications of two-dimensional MOF nanosheet approach. This work contributes to develop the research on two-dimensional MOF nanosheets materials with targeted and specific recognition for the biological and environmental luminescent sensors.

Co-catalyst loading provides an effective way to enhance the efficiency of photocatalysts for solar hydrogen production. From a sustainability point of view, it has immense scientific and technological values to explore more efficient co-catalytic systems by using multi-cocatalysts, because of potential synergetic effects between different components. Herein, the feasibility of using Ti3C2 MXene nanoparticles and Pt nanoclusters as dual co-catalysts to enhance the photoactivity of g-C3N4 for H2 production was investigated. Due to the improved electrical conductivity and increased reactive sites for photoreduction reactions, Ti3C2 and Pt co-modified photocatalysts exhibited a high photocatalytic hydrogen production activity of 5.1 mmol h-1 g-1. Compared to g-C3N4/Ti3C2 and g-C3N4/Pt, the 3- and 5-fold increased photoactivity demonstrated great potential of Ti3C2 MXene nanoparticles to construct high-performance photocatalysts. The synergetic effects between Ti3C2 and Pt were fundamentally investigated, indicating that the specific transfer of electrons not only contributed to the inhibited recombination of charge carriers but also resulted in good stability of heterostructured photocatalysts. Our results have demonstrated an approach worthy for the design and fabrication of high-efficiency heterostructures with superior photoactivity for hydrogen energy production.