Colloidal Synthesis and Photocatalytic Properties of Cu3NbS4 and Cu3NbSe4 Sulvanite Nanocrystals.

ABSTRACT

Niobium sulvanites Cu3NbX4 (X = S, Se) have been theoretically predicted as promising candidates for solar photovoltaics and photocatalytic water splitting. This report outlines the first synthesis of Cu3NbS4 and Cu3NbSe4 in a nanocrystalline form. The crystal structures were investigated by X-ray diffraction, identity was confirmed by Raman spectroscopy, and the optoelectronic properties and morphology of Cu3NbS4 and Cu3NbSe4 nanocrystals were examined by UV-vis spectroscopy and transmission electron microscopy, respectively. To gain insight into the Cu3NbX4 formation, a mechanistic study was conducted for Cu3NbSe4 monitoring the nanoparticles' formation as a function of reaction time. Methylene blue photodegradation tests were conducted to evaluate the photoactivity of Cu3NbS4 and Cu3NbSe4. The degradation rates, 2.81 × 10-2 min-1 and 1.22 × 10-2 min-1 proved the photocatalysts' potential of nanoscale Cu3NbX4.