Colloidal Synthesis and Photocatalytic Properties of CuNbS and CuNbSe Sulvanite Nanocrystals.

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