Tamara V. Gavrilović

Multifunctional Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles synthesized by reverse micelle method

Synthesis of Eu3+- and Er3+/Yb3+-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microscopy is similar to the crystallite size obtained from X-ray diffraction measurements, suggesting that each particle comprises a single crystallite. Eu3+-doped GdVO4 nanoparticles emit red light through downconversion upon UV excitation. Er3+/Yb3+-doped GdVO4 nanoparticles exhibit several functions; apart from the downconversion of UV radiation into visible green light, they act as upconvertors, transforming near-infrared excitation (980 nm) into visible green light. The ratio of green emissions from 2H11/2 → 2I15/2 and 4S3/2 → 4I15/2 transitions is temperature dependent and can be used for nanoscale temperature sensing with near-infrared excitation. The relative sensor sensitivity is 1.11%K−1, which is among the highest sensitivities recorded for upconversion-luminescence-based thermometers.

Synthesis of Multifunctional Inorganic Materials: From Micrometer to Nanometer Dimensions

Abstract Both, novel and older widely and routinely used methods of chemical synthesis fornew multifunctional inorganic (nano) materials with different sizes and morphologies are reviewed and summarized in this chapter. Illustrative examples of micro- and nanoparticle preparations are provided regarding different applications: renewable and sustainable energy harvesting, water splitting and hydrogen generation, fuel and solar cell devices, luminescent materials for white light–emitting diodes and clean environment. We give our perspective on the current status of the topic: methods of colloidal chemistry, coprecipitation, reverse-micelle technique, sol–gel, spray pyrolysis, microwave-assisted hydrothermal/solvothermal method, and high-temperature solid-state method are covered in more detail and more emphasis is placed on methods of synthesis, steps involved in experimental procedure and applicability, advantages, and disadvantages of each synthetic approach.

Synthesis, structure and spectroscopic assessment of luminescent GdVO4:Dy3+ and DyVO4 nanoparticles

In this paper, we focused on the size effects of GdVO4:2mol% Dy3+ and DyVO4 particles on their structural and optical properties. Highly crystalline particles of different sizes and morphologies with tetragonal zircon-type phase were successfully synthesized by using different techniques of synthesis, such as reverse micelles, co-precipitation and hightemperature solid-state methods. The prepared samples exhibited a number of similarity and diversity in structural and optical properties with a decreasing in particle diameter.