Bio-surfactant mediated sustainable exfoliation of MoS2 and in-situ preparation of Ag@MoS2 nanocomposites for photocatalysis under sunlight in aqueous medium

Abstract

Exfoliation of MoS2 has been performed in the aqueous solution of bio-based surfactant choline deoxycholate, ([Cho][Doc]), employing low-energy bath sonication. The ability of [Cho]+ to reduce the Ag+ under sunlight accompanied by the templating effect of [Doc]− has been exploited to decorate the exfoliated MoS2 in a single step. The dimensions as well as the extent of adherence of Ag NPs to MoS2 in Ag@MoS2 nanocomposites (NCs) have been controlled by adjusting the concentration of [Cho][Doc]. The prepared NCs have been characterized by UV–vis spectroscopy, atomic force microscopy (AFM), dynamic light scattering (DLS), zeta-potential measurements (ζ-potential), X-ray diffraction (XRD), Raman spectroscopy, X-ray photon spectroscopy (XPS), transmission (TEM) and high-resolution transmission electron microscopy (HR-TEM). The NCs have shown enhancement in photocatalytic activity compared to bare Ag NPs under sunlight in an aqueous medium. It has been observed that the Schottky junction between metallic Ag NPs and semiconductor MoS2 in NCs shows efficient charge separation by generating a continuum-charged region resulting in increased catalytic activity of NCs. The present work is expected to serve as a platform for preparing photocatalytic NCs sustainably employing various other 2D materials.