A general hydrothermal method was developed to prepare colloidal gadolinium orthovanadate nanocrystals by using supercritical water as a green solvent. The spectacular properties of supercritical water is advantageous for synthesizing crystalline and surface-modified luminescent nanoparticles capped with long alkyl chains of organic modifiers on the surface of the particles to make them dispersible in nonpolar solvents. The size of the nanoparticles could be controlled within 10-15 nm. Characterization of the hydrothermal product was accomplished using X-ray diffraction, transmission electron microscopy (TEM), high-resolution TEM, Fourier transform infrared spectroscopy, thermo gravimetric analysis, and electron dispersive X-ray scattering. The photoluminescence characterization showed that there is a strong red emission under UV excitation, which broadens the material's various applications.
- Supercritical water
- Surface modification