Ziqi Wang

Dual-emitting MOF⊃dye composite for ratiometric temperature sensing.

A strategy to achieve a ratiometric thermometer by encapsulating luminescent perylene dye into the pores of a europium metal-organic framework (MOF) is developed. The resulting MOF⊃dye thermometer exhibits highly temperature-dependent luminescence intensity ratio over the physiological temperature range, with a maximum sensitivity of 1.28% °C(-1) at 20 °C.

Porous anatase TiO2 constructed from a metal–organic framework for advanced lithium-ion battery anodes

Porous anatase TiO2 has been prepared, for the first time, through the calcination of a metal–organic framework (MOF) precursor under an air atmosphere at 380 °C. The resulting TiO2 has shown moderate porosity with a BET surface area of 220 m2 g−1 attributed to the highly porous structure of the MIL-125(Ti) precursor. The porous anatase TiO2 was examined as a lithium-ion battery anode, exhibiting high capacity retention and good rate capability. The porous structure of anatase TiO2 enforces Li+ diffusion and helps to buffer the volumetric variation. It has shown reversible capacities of 166, 106 and 71 mA h g−1 at 1 C, 5 C and 10 C charge/discharge rates, respectively, after 500 cycles.

Mixed-Metal–Organic Framework with Effective Lewis Acidic Sites for Sulfur Confinement in High-Performance Lithium–Sulfur Batteries

The mixed-metal-organic framework approach and a representative zirconium-metalloporphyrin framework (MOF-525) have been developed to create novel sulfur hosts and Li-S batteries. The different local environments at the centers of the porphyrin moieties in a series of MMOFs-MOF-525(2H), MOF-525(FeCl), and MOF-525(Cu)-have led to their different behaviors for the confinement of sulfur and thus Li-S batteries. The unique structure of MOF-525(Cu) has enabled each Cu(2+) site to offer two Lewis acidic sites, featuring it as a very powerful MOF host for the inclusion of sulfur and polysulfides. The S@MOF-525(Cu) cathode has demonstrated the best performance among all reported sulfur/MOFs composite cathode materials, with a reversible capacity of about 700 mAh/g at 0.5 C after 200 cycles.

Highly dispersed β-NiS nanoparticles in porous carbon matrices by a template metal–organic framework method for lithium-ion cathode

By calcination of MOF-74(Ni) under reducing environments, nanosized Ni particles (5–10 nm) in carbon matrices were obtained, which were converted into NiS through an in situ reaction. Featuring small particle sizes (∼50 nm), uniform distribution and porosity, C ⊃ NiS was preliminarily studied as lithium-ion cathode material, which has shown electrochemical performance superior to that of bare NiS.

Electrochemical properties of SnO2 nanoparticles immobilized within a metal–organic framework as an anode material for lithium-ion batteries

SnO2 nanoparticles have been immobilized inside MIL-101(Cr) crystals achieving the novel SnO2@MIL-101(Cr) anode material with a multiple-core/shell structure. Under the protection of MIL-101(Cr) shell, the pulverization and aggregation of SnO2 during cycling have been diminished. Both good cyclability and rate capability with a reversible capacity of ∼510 mA h g−1 at 0.1C after 100 cycles have revealed.

Designed fabrication of anatase mesocrystals constructed from crystallographically oriented nanocrystals for improved photocatalytic activity

In this article, we report a new route to synthesize octahedral anatase mesocrystals (MCs), polycrystals (PCs) and single crystals (SCs) in the TiCl4–CH3COOH system just by tuning the reaction time and Ti-source concentration. Owing to the unique structures constructed from crystallographically oriented nanocrystals, MCs offer larger specific surface area than SCs and more effective electron transport compared with PCs. As anticipated, MCs show the highest photocatalytic activity in the degradation of methylene blue. MCs also demonstrate excellent cycle stability and renewable capability, and the photocatalytic efficiency still remains up to 90% even after five cycles. The designed fabrication of mesocrystals provides an attractive and effective route for improving the performances of semiconductor photocatalysts.