LAUSR

Abstract Highly dispersible, uniform size (∼7 nm) single-phase Cu 2 ZnSnS 4 nanoparticles have been synthesized by hydrothermal method using non-toxic surfactant (oleic acid). High resolution transmission electron microscopy image indicates good crystallinity of the Cu 2 ZnSnS 4 nanoparticles with the growth along (1 1 2) plane. X-ray photoelectron spectroscopy analyses suggested that the formation of with Cu, Zn, and Sn in +1, +2 and +4 oxidation states. The optical absorption spectrum of Cu 2 ZnSnS 4 nanoparticles exhibits an absorption in the visible region and its optical band gap was found to be ∼1.72 eV, which could be much more appropriate for photocatalytic application under visible light irradiation. These Cu 2 ZnSnS 4 nanoparticles have been shown high photocatalytic degradation activity of methylene blue (MB) dye in the presence of visible light irradiation. The rate constant ( k ) value of Cu 2 ZnSnS 4 nanoparticles is found to be 0.0144 min −1 . We have discussed the mechanism of dye degradation process that drives the photocatalytic degradation process. The reusability of the Cu 2 ZnSnS 4 nanoparticles for the dye degradation is also demonstrated.