Optical Properties of Yttria-Stabilized Zirconia Single-Crystals Doped with Terbium Oxide

A series of yttria-stabilized zirconia single-crystals doped with 0.000–0.250 mol% Tb4O7 was prepared by the optical floating-zone method. As shown by XRD and Raman spectroscopy, all of the crystals had a cubic-phase structure. These were initially orange–yellow in color, which is indicative of the presence of Tb4+ ions, but they then became colorless after being annealed in a H2/Ar atmosphere as a result of the reduction of Tb4+ to Tb3+. The absorption spectra of the unannealed samples show both the 4f 8→4f 75d1 transition of Tb3+ ions and the Tb4+ charge-transfer band. In addition, the transmittance of the crystals was increased by annealing. Under irradiation with 300 nm of light, all of the single-crystal samples showed seven emission peaks in the visible region, corresponding to the decay from the 5D3,4 excited state of Tb3+ to the 7FJ (J = 6–0) states. The most intense emission was at 544 nm, which corresponds to the typical strong green emission from the 5D4→7F5 transition in Tb3+ ions.

Interface/defect-tuneable macro and micro photoluminescence behaviours of trivalent europium ions in electrospun ZrO2/ZnO porous nanobelts

It was demonstrated that suitable interfaces between two materials can enhance the separation of photogenerated carriers. In this study, ZrO₂/ZnO interfaces with type I structure were designed and prepared by the electrospinning technique. The obtained ZrO₂/ZnO:Eu³⁺ (ZZOE) composites are highly porous in the form of nanobelts with width of 600-700 nm, comprising ZnO and ZrO₂ nanocrystals, and the Eu doping can hinder the t-m phase transition of ZrO₂. By tuning the annealing temperature, the inner stress and defects can be well controlled to improve the photoluminescence (PL) of the ZZOE porous nanobelts. Macro- and micro-PL spectra indicated that the body oxygen vacancies benefit the PL from Eu³⁺ ions, whereas the surficial ones do not. The optimal parameters for the preparation of ZZOE porous nanobelts were also investigated. Finally, a charge transfer mechanism was proposed to illuminate the PLs from the ZZOE porous nanobelts.

In-water facile synthesis of poly-substituted 6-arylamino pyridines and 2-pyrrolidone derivatives using tetragonal nano-ZrO2 as reusable catalyst

Green synthesis of functionalized 6-arylamino pyridines and 2-pyrrolidinone derivatives using tetragonal ZrO₂ nanoparticles as reusable catalyst in aqueous ethanol.

On water synthesis of pyran–chromenes via a multicomponent reactions catalyzed by fluorescent t-ZrO2nanoparticles

Here, we have reported multicomponent synthesis of diverse pyran fused chromenes namely 2-aminochromene, dihydropyrano[3,2-c]chromene, and chromeno[4,3-b]chromene derivatives using fluorescentt-ZrO₂nanoparticles as reusable catalyst in water.