SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium

In this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and microscopic techniques, namely X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TEM images of the MoS2/SnO2 revealed that SnO2 nanoparticles were embedded into MoS2. Furthermore, photodegradation mechanism and the role of adsorption were discussed. The enhanced photocatalytic performance of MoS2/SnO2 composite can be directly attributed to the presence of SnO2, which may increase the separation efficiency of the electron-hole pairs. The 99.5% of MB removal was achieved after 5 minutes of illumination. To the best of our knowledge, it is one of the most photoactive MoS2-based photocatalysts for methylene blue (MB) photodecomposition. Moreover, the obtained composite was highly active against chromium (VI) photo-reduction. This work provides evidence that the MoS2/SnO2 composite possesses enormous potential in photocatalytic applications.