Short Time and Low Temperature Reaction between Metal Oxides through Microwave-Assisted Hydrothermal Method

Abstract

This work demonstrates the possibility of synthesis of cadmium tungstate at low temperatures using oxide precursors. Cadmium tungstate (CdWO4) scintillator was produced via microwave-assisted hydrothermal reaction using the precursors CdO and WO3. The methodology was based on microwave radiation for heating, which is remarkably faster than the solid-state route or conventional hydrothermal procedure. CdWO4 monoclinic (wolframite) structure was successfully obtained at 120°C for synthesis times as short as 20 min. This route does not require the use of templates or surfactants and yields self-assembled nanorods with size of around 24 ± 9 nm width and 260 ± 47 nm length. The growth mechanism for the formation of CdWO4 involves microwave-induced dissociation of the reagents and solvation of Cd2+ and WO42- ions, which are free to move and start the nucleation process. The luminescence properties of the produced nanoparticles were investigated, presenting a broad emission band at around 500 nm, which is comparable to that observed for samples produced using other chemical routes. This result highlights the great potential of the proposed method as a low-cost and time saving process to fabricate luminescent oxide nanoparticles.

Facile Microwave Hydrothermal Synthesis of ZnFe2O4/rGO Nanocomposites and Their Ultra-Fast Adsorption of Methylene Blue Dye

“…However, the heating process of the microwave hydrothermal method uses the electromagnetic wave to directly heat the samples in the vessel. This method reduces the energy lost in the heating process and decreases the time needed considerably [ 33 ]. The time cost in sample synthesis via the microwave hydrothermal method is usually less than one hour.…”

Effect of Amino and Carboxyl Functionalization on the Photoluminescence Properties of Rice Husk-Derived Carbon Quantum Dots (RH-CQDs)

“…Hence, for this study, rice husk is used as the precursor to synthesize carbon quantum dots due to its abundancy in environment, low cost, facile preparation method when compared to others biowaste precursors. Hydrothermal method, a bottom-up approach is commonly used in synthesizing the carbon quantum dots from natural precursor due to its facile synthesis, low cost and controlled morphology advantages [16].…”