Facile synthesis of MoS2 nanoparticles anchored graphene nanocomposite for enhanced photocatalytic activity under solar irradiation

Abstract

In the face of a growing scarcity of water resources, the design of photocatalysts that are easily recovered eco-friendly and cost-effective is an indispensable priority. In this study, nanolayer Reduced Graphene Oxide-MoS2 nanocomposites were fabricated by a modified Hummer method followed by a solvothermal method. The fabricated nanocomposite materials were thoroughly analyzed by UV-Vis-DRS, FE-SEM, FT-IR, XPS XRD, EPR, EIS, HR-TEM, Raman and BET analyses. RGO-MoS2 nanocomposite possessed a higher surface area (164.4 m2 g−1) which is highest surface area for RGO-MoS2 nanocomposite reported so far. Under solar light irradiation, the RGO-MoS2 nanocomposite degraded 99 % of the AB 10B dye molecules in 60 min. In a comparison study for non-azo dyes, the maximum degradation was found to be 99 % at 25 and 30 min for methylene blue and Rhodamine B dye, respectively. The main components of the degradation processes of AB 10B dye molecules are (•OH) hydroxyl radicals and (•O2−) superoxide radicals have been identified using electron paramagnetic resonance spectroscopy (EPR). EIS Nyquist diagram of RGO-MoS2 nanocomposites showed better charge transport characteristics than neat MoS2. RGO-MoS2 nanocomposite photocatalyst have higher photocatalytic activity owing to suppressed recombination rate of photogenerated e−/h+ pairs and narrow bandgap. The degradation products were analyzed with GC-MS and a plausible photodegradative mechanism for the degradation of AB 10B dye were proposed. Considering, these findings the excellent photocatalytic performance and easy recovery the RGO-MoS2 nanocomposite is an attractive and inexpensive photocatalyst for environmental remediation applications.