Colloidal Synthesis and Photocatalytic Properties of Cu 3 NbS 4 and Cu 3 NbSe 4 Sulvanite Nanocrystals.

Niobium sulvanites Cu 3 NbX 4 (X = S, Se) have been theoretically predicted as promising candidates for solar photovoltaics and photocatalytic water splitting. This report outlines the first synthesis of Cu 3 NbS 4 and Cu 3 NbSe 4 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 Cu 3 NbS 4 and Cu 3 NbSe 4 nanocrystals were examined by UV-vis spectroscopy and transmission electron microscopy, respectively. To gain insight into the Cu 3 NbX 4 formation, a mechanistic study was conducted for Cu 3 NbSe 4 monitoring the nanoparticles' formation as a function of reaction time. Methylene blue photodegradation tests were conducted to evaluate the photoactivity of Cu 3 NbS 4 and Cu 3 NbSe 4 . The degradation rates, 2.81 × 10 -2 min -1 and 1.22 × 10 -2 min -1 proved the photocatalysts' potential of nanoscale Cu 3 NbX 4 .