State Key Laboratory of Luminescence and Application

In the past few decades, there has been a wide research interest in titanium dioxide (TiO2) nanomaterials due to their applications in photocatalytic hydrogen generation and environmental pollution removal. Improving the optical absorption properties of TiO2 nanomaterials has been successfully demonstrated to enhance their photocatalytic activities, especially in the report of black TiO2 nanoparticles. The recent progress in the investigation of black TiO2 nanomaterials has been reviewed here, and special emphasis has been given on their fabrication methods along with their various chemical/physical properties and applications.

The garnet Ca₂LuZr₂Al₃O₁₂ (CLZA) is a promising broad-band NIR phosphor for blue LED chips when it is doped with Cr³⁺.

A two-dimensional cationic covalent organic framework membrane with extraordinary separation properties and high permeability.

Recent efforts and progress in unraveling the fundamental mechanism of excitation energy migration dynamics in upconversion nanomaterials are covered in this review, including short- and long-term interactions and other interactions in homogeneous and heterogeneous nanostructures. Comprehension of the role of spatial confinement in excitation energy migration processes is updated. Problems and challenges are also addressed.

Fluorescent carbon dots (CDs) with a size smaller than 10 nm, excellent biocompatibility, and low to no cytotoxicity are considered as a rising star in nanomedicine. In this report, for the first time we demonstrate that green-emitting CDs with a carboxyl-rich surface can be employed as a trackable drug delivery agent for localized cancer treatment in a mouse model. The CDs are conjugated with the cancer drug, Doxorubicin (DOX), via non-covalent bonding, utilizing the native carboxyl groups on CDs and the amine moiety on DOX molecules. The pH difference between cancer and normal cells was successfully exploited as the triggering mechanism for DOX release. Our in vivo study demonstrated that the fluorescent CDs can serve as a targeted drug delivery system for localized therapy, and the stimuli-responsive non-covalent bonding between the nanodot carrier and the drug molecule is sufficiently stable in complex biological systems. Taken together, our work provides a strategy to promote the potential clinical application of CDs in cancer theranostics.

The photoluminescence stability of all-inorganic perovskite nanocrystals (CsPbBr₃) with different size is studied.

The Ba₉Lu₂Si₆O₂₄:Ce³⁺cyan phosphor has excellent luminescence properties and displays promising application in NUV-based white LEDs with high performance.

We demonstrate a novel ZnO self-powered photodetector based on the asymmetric metal-semiconductor-metal structure: one Au interdigitated electrode with wide fingers and the other one with narrow fingers.

The in vivo biological applications of upconversion nanoparticles (UCNPs) prefer excitation at 700-850 nm, instead of 980 nm, due to the absorption of water. Recent approaches in constructing robust Nd(3+) doped UCNPs with 808 nm excitation properties rely on a thick Nd(3+) sensitized shell. However, for the very important and popular Förster resonance energy transfer (FRET)-based applications, such as photodynamic therapy (PDT) or switchable biosensors, this type of structure has restrictions resulting in a poor energy transfer. In this work, we have designed a NaYF4:Yb/Ho@NaYF4:Nd@NaYF4 core-shell-shell nanostructure. We have proven that this optimal structure balances the robustness of the upconversion emission and the FRET efficiency for FRET-based bioapplications. A proof of the concept was demonstrated for photodynamic therapy and simultaneous fluorescence imaging of HeLa cells triggered by 808 nm light, where low heating and a high PDT efficacy were achieved.

A visual colorimetric dipicolinic acid sensor was prepared by modulating the energy transfer process in the MOF.

Red upconversion luminescence (UCL) is selectively enhanced by about 7 times via Fe(3+) codoping into a NaYF4:Yb,Er nanocrystalline lattice. The maximum red-to-green ratio (R/G) as well as the overall integrated UCL intensity features at an Fe(3+) content of 20 mol%. The size and phase of nanocrystals are simultaneously manipulated via Fe(3+) doping with various concentrations by a facile hydrothermal method. Contrary to the literature, the pure hexagonal phase appears when Fe(3+) concentrations are from 5 to 20 mol%, meanwhile, the size of NaYF4:Yb,Er nanocrystals reaches its maximum at 10 mol%. The intensified visible UCL especially the dominant red emission is mainly ascribed to the energy transfer (ET) from |(2)F7/2, (4)T1g > (Yb(3+)-Fe(3+) dimer) to (4)F9/2 (Er(3+)) states as well as the distortion of the crystalline field symmetry upon Fe(3+) codoping. Dynamic investigation of (4)S3/2 and (4)F9/2 states under the pulsed laser excitation of 980 nm along with the diffuse reflectance data further supports the proposed mechanism of UC processes. The results show the remarkable promise of Fe(3+)-codoped NaYF4:Yb,Er nanocrystals as upconverting nanoprobes with high sensitivity and penetrability in deeper tissue for multimodal biomedical imaging.

Taking advantage of the cooperation between the excitonic transition of the CsPbCl₃ perovskite NC host and the intrinsic emissions from Bi³⁺ and Mn²⁺ ions, white light emission was developed in the codoped CsPbCl₃ NCs.

MOFs-derived micro/nanostructures have important potential applications. In this review, we describe the use of MOFs as templates in the synthesis of metal/metal oxide micro/nanostructures and composite materials. The applications of the derived materials are also reviewed.

Bright red upconversion phosphor Ba₃Y₄O₉:Er³⁺/Yb³⁺ and dual-color complementary optical thermometry to maintain relatively high sensitivities over a wide temperature scope.

Stable reduced TiO2 rutile nanorods with well-defined facets were prepared by a solvothermal route in the presence of Zn powder. The oxygen vacancy in the TiO2 nanorods, which can be tuned by the amount of Zn, results in a narrow band gap and visible-light photocatalytic activity.

A novel RGH–MOF system was prepared for ratiometric sensing of picric acid. The color changes can be observed by the naked eye.

Hydrogenation largely improves the microwave absorbing efficiency of BaTiO₃ nanoparticles.

High-efficiency excimer fluorescence of <bold>mTPA-9-AN</bold> is realized by a thermally-activated phase transition process.

Combined photoluminescence and impedance spectroscopy studies show that a europium-based metal-organic framework behaves as a highly effective and reliable humidity sensor, enabling dual-mode humidity detection.

with an optimal amount of defects exhibits highly enhanced photocatalytic performance. An excess amount of defects results in a weak SPS response and photocatalytic performance.