Hydrothermal Synthesis of Phase-Pure Sulvanite Cu₃VS₄ Nanoparticles

The successful synthesis of sulvanite nanoparticles has opened avenues for a wide range of new applications for these materials. Currently, the synthesis of sulvanite Cu₃VS₄ nanoparticles is accomplished via hot injection methods, which are nonscalable and lead to retention of ligands on the surface of the particles. This could prove detrimental to performance in advanced material applications as it requires subsequent purification or surface modifications of the nanoparticles to remove ligands. In this work, we demonstrate a sustainable method for producing ligand free-Cu₃VS₄ nanoparticles in a one-step procedure, utilizing a hydrothermal synthetic approach. A temperature study revealed that the optimal temperature of 220 °C required for producing pure Cu₃VS₄ nanoparticles is moderate and below the typical colloidal synthesis temperature, further pointing to the increased energy efficiency of the process. X-ray powder diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy validated the identity and crystallinity of Cu₃VS₄ nanoparticles synthesized through this method and demonstrated the absence of ligands on the surface of the material. Ultraviolet-visible spectroscopy was utilized to determine the material absorbance via diffuse reflectance revealing an indirect bandgap of 1.46 eV. Transmission electron microscopy analysis showed a narrow particle size distribution, with particle size below 30 nm. These results demonstrate the potential of a new approach to producing high-quality sulvanite Cu₃VS₄ nanoparticles for applications in optoelectronics, catalysis, and energy storage.