Two-dimensional molybdenum disulphide nanoflakes synthesized by liquid-solid phase reaction method: regenerative photocatalytic performance under UV-visible light irradiation by advance oxidation process

Abstract

Molybdenum disulphide (MoS2) nanoflakes were prepared through liquid-solid phase reaction technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM) analysis revealed the formation of pure, polycrystalline, hexagonal phase of MoS2 nanoflakes. The texture coefficient ($T{c}_{hkl}$) analysis showed that (100) plane was preferentially oriented. The specific surface area of the nanoflakes was 21 m2 g−1 as determined using Brunaure-Emmett-Teller (BET) technique. A band gap of ~2.05 eV for MoS2 nanoflakes was estimated from UV-visible spectrum. Regenerative photocatalytic activity of MoS2 nanoflakes was assessed by degrading methylene blue (MB) and safranin-o (SO) dyes under UV-visible light irradiation. Under light irradiation, degradation efficiency for MB was ~99.58% in 100 min while for SO it was ~99.89% in 70 min. The MoS2 nanoflakes exhibited excellent photocatalytic performance and good stability in a wide pH range (3–11). MoS2 nanoflakes showed a high reaction rate constant (k app ) for SO ~ 0.104 49 min−1 and MB ~ 0.092 18 min−1 as compared to other MoS2 nanostructures. The obtained exceptional photocatalytic performance of MoS2 nanoflakes offers potential applications for the treatment of polluted water as well as in other correlated fields.