Upconversion luminescence properties of BaMoO4: Yb3+, Ln3+ (Ln3+ = Er3+/Tm3+, Er3+/Tm3+/Ho3+) micro-octahedrons

Yb³⁺, Ln³⁺ (Ln³⁺ = Er³⁺/Tm³⁺, Er³⁺/Tm³⁺/Ho³⁺) doped BaMoO₄ micro-octahedrons were synthesized by a hydrothermal process. The as-prepared phosphors were characterized by x-ray powder diffraction, field emission scanning electron microscopy, elemental mapping, energy-dispersive x-ray spectroscopy, x-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The upconversion luminescence properties of the samples were investigated under 980 nm near infrared excitation. The different concentrations of Er³⁺, Tm³⁺, and Ho³⁺ were used for tuning the multicolor (blue, green, and red) emissions. The multicolor emissions were investigated by Commission Internationale de l'Elcairage chromaticity and decay lifetime. The photon process as well as the energy transfer mechanism between the Yb³⁺ to Er³⁺, Tm³⁺, and Ho³⁺ were described.

Lanthanide-Doped Photoluminescence Hollow Structures: Recent Advances and Applications

Lanthanide-doped nanomaterials have attracted significant attention for their preeminent properties and widespread applications. Due to the unique characteristic, the lanthanide-doped photoluminescence materials with hollow structures may provide advantages including enhanced light harvesting, intensified electric field density, improved luminescent property, and larger drug loading capacity. Herein, the synthesis, properties, and applications of lanthanide-doped photoluminescence hollow structures (LPHSs) are comprehensively reviewed. First, different strategies for the engineered synthesis of LPHSs are described in detail, which contain hard, soft, self-templating methods and other techniques. Thereafter, the relationship between their structure features and photoluminescence properties is discussed. Then, niche applications including biomedicines, bioimaging, therapy, and energy storage/conversion are focused on and superiorities of LPHSs for these applications are particularly highlighted. Finally, keen insights into the challenges and personal prospects for the future development of the LPHSs are provided.

Hydrothermal synthesis, characterization and luminescence properties of CaGd2(MoO4)4:Eu3+ ovoid like structures

Red light emission from CaGd₂(MoO₄)₄:0.06Eu³⁺ phosphor by EDTA assisted hydrothermal route at 200 °C for 24 h.

Ytterbium-erbium ion doped strontium molybdate (SrMoO4): synthesis, characterization, photophysical properties and application in solar cells

In this work, ytterbium-erbium co-doped strontium molybdate (SrMoO₄, SMO) nanophosphors (NPs), denoted as SMO:Yb/Er, have been successfully prepared. These NPs were then incorporated into TiO₂ acceptor films in hybrid solar cells to enhance light harvesting by virtue of an up-conversion process where low energy photons can be converted into high energy photons through multi-photon processes. The results showed that the SMO:Yb/Er single crystal NPs are capable of turning near infrared photons into visible ones that can be easily captured by poly(thieno[3,4-b]-thiophene/benzodithiophene) (PTB7). The results indicate that the electron transfer rate at the PTB7/TiO₂ donor/acceptor interface has been boosted sharply from 0.59 to 1.35 × 10⁹ s^-1. Consequently, a hybrid solar cell based on SMO:Yb/Er NP-doped TiO₂/PTB7 delivers a high power conversion efficiency of up to 3.61%, thus leading to an efficiency enhancement of around 28% as compared to that of the neat PTB7/TiO₂ counterpart (2.81%). This work demonstrates a promising approach to engineering efficient photovoltaic devices by taking advantage of the versatility of rare-earth ion doped oxides that function by modifying light in the solar spectrum.

Hollow mesoporous Gd2O3:Eu3+ spheres with enhanced luminescence and their drug releasing behavior

Hollow mesoporous nanospheres Gd₂O₃:Eu³⁺ could be well fabricated by CCPS templates, which exhibited a durable drug release property.

Synthesis, up-conversion luminescence and thermometry of Yb3+/Er3+ co-doped La2.4Mo1.6O8 phosphors

Synthesis, up-conversion luminescence properties and temperature-sensing application of La_2.4Mo_1.6O₈:Yb³⁺/Er³⁺ phosphors have been investigated using FIR technique.

pH-Triggered SrTiO3:Er Nanofibers with Optically Monitored and Controlled Drug Delivery Functionality

The design of multifunctional localized drug delivery systems (LDDSs) has been endeavored in the past decades worldwide. The matrix material of LDDSs is known as a crucial factor for the success of its transformation from the laboratory to clinical practices. Herein, a biocompatible ceramic, strontium titanate (SrTiO3, STO), was utilized as the matrix. A variety of fine Er doped SrTiO3 (STO:Er) nanofibers were fabricated via electrospinning. After the surface functionalization with amino groups, the drug loading capacity of STO:Er nanofibers is dramatically increased. The nanofibers present a rather sustained drug releasing behavior in the media with pH of 7.4, and the release kinetics is significantly accelerated with the decreased pH value from 7.4 to 4.7. Furthermore, the intensity of the spectrum emitted from the STO:Er nanofibers corresponds well with the drug releasing progress under the excitation of near-infrared spectrum (∼980 nm). Fast drug release behavior (in an acid environment) induces a rapid intensity enhancing effect of photoluminescence emission and vice versa. The main mechanism is attributed to the quenching effect induced by the C-Hx groups of IBU molecules with vibration frequencies from 2850 to 3000 cm(-1). Such new STO:Er nanofibers with pH-triggered and optically monitored drug delivery functionalities have therefore been considered as another new localized drug delivery platform for modern tumor diagnosis and therapy.

Luminescent hollow CaWO4 microspheres: template-free synthesis, characterization and application in drug delivery

Luminescent hollow structural CaWO₄ microspheres prepared by a template-free method show a sustained-release property for IBU.

Current advances in lanthanide ion (Ln3+)-based upconversion nanomaterials for drug delivery

This review mainly focuses on the recent advances in various chemical syntheses of Ln³⁺-based upconversion nanomaterials, with special emphasis on their application in stimuli-response controlled drug release and subsequent therapy.

Photoluminescence and photocatalytic activity of monodispersed colloidal “ligand free Ln3+-doped PbMoO4 nanocrystals”

Ligand free monodisperse Ln³⁺ doped PbMoO₄ nanocrystals as efficient photocatalyst and phosphor.

Energy transfer dynamics and luminescence properties of Eu3+ in CaMoO4 and SrMoO4

Undoped and europium doped CaMoO₄ and SrMoO₄ scheelites are synthesized using a complex polymerization method.

Er3+-doped YbPO4 up-conversion porous nanospheres for UCL/CT bimodal imaging in vivo and chemotherapy

PEI modified up-conversion porous nanospheres were obtained by template-free hydrothermal method, combining up-conversion luminescence/X-ray computed tomography bimodal-imaging with drug delivery.

Bilayer stabilized Ln3+-doped CaMoO4 nanocrystals with high luminescence quantum efficiency and photocatalytic properties

In this article, we discuss the microwave synthesis of sodium dodecyl sulphate (SDS) stabilized Ln³⁺-doped CaMoO₄ nanocrystals (Ln³⁺ = Eu³⁺, Er³⁺/Yb³⁺).

Lanthanide-doped hollow nanomaterials as theranostic agents

The field of theranostics has sprung up to achieve personalized medicine. The theranostics fuses diagnostic and therapeutic functions, empowering early diagnosis, targeted drug delivery, and real-time monitoring of treatment effect into one step. One particularly attractive class of nanomaterials for theranostic application is lanthanide-doped hollow nanomaterials (LDHNs). Because of the existence of lanthanide ions, LDHNs show outstanding fluorescent and paramagnetic properties, enabling them to be used as multimodal bioimaging agents. Synchronously, the huge interior cavities of LDHNs are able to be applied as efficacious tools for storage and delivery of therapeutic agents. The LDHNs can be divided into two types based on difference of component: single-phase lanthanide-doped hollow nanomaterials and lanthanide-doped hollow nanocomposites. We describe the synthesis of first kind of nanomaterials by use of hard template, soft template, template-free, and self-sacrificing template method. For lanthanide-doped hollow nanocomposites, we divide the preparation strategies into three kinds (one-step, two-step, and multistep method) according to the synthetic procedures. Furthermore, we also illustrate the potential bioapplications of these LDHNs, including biodetection, imaging (fluorescent imaging and magnetic resonance imaging), drug/gene delivery, and other therapeutic applications.