MoS$_{2}$ nanosheets incorporated {\alpha}-Fe$_{2}$O$_{3}$/ZnO nanocomposite with enhanced photocatalytic dye degradation and hydrogen production ability

TL;DR

This study demonstrates that incorporating ultrasonically exfoliated MoS$_{2}$ nanosheets into $eta$-Fe$_{2}$O$_{3}$/ZnO nanocomposites significantly enhances their photocatalytic efficiency for dye degradation and hydrogen production under solar illumination.

Contribution

It introduces a novel synthesis of MoS$_{2}$ incorporated $eta$-Fe$_{2}$O$_{3}$/ZnO nanocomposites with improved photocatalytic performance due to ultrasonication.

Findings

Achieved 91% dye degradation efficiency under solar light.

Enhanced hydrogen production compared to non-ultrasonicated composites.

Suppressed electron-hole recombination due to MoS$_{2}$ incorporation.

Abstract

We have synthesized MoS$_{2}$ incorporated $\alpha$-Fe$_{2}$O$_{3}$/ZnO nanocomposites by the hydrothermal process. The effect of incorporating ultrasonically exfoliated MoS$_{2}$ on the photocatalytic performance of $\alpha$-Fe$_{2}$O$_{3}$/ZnO nanocomposites has been demonstrated. Structural, morphological and optical characteristics of the nanomaterials are investigated by performing Rietveld refinement of powder X-ray diffraction patterns, field emission scanning electron microscopy and UV-visible spectroscopy. The photoluminescence spectra of the nanocomposites show that the recombination of photogenerated electron-hole pairs is suppressed due to incorporating MoS$_{2}$ nanosheets. The ultrasonicated MoS$_{2}$ incorporated $\alpha$-Fe$_{2}$O$_{3}$/ZnO nanocomposite shows 91% and 83% efficiency to degrade RhB dye and antibiotic ciprofloxacin under solar illumination. Active species trapping experiments reveal that the hydroxyl radicals play a significant role in RhB degradation. Likewise, the dye degradation efficiency, the amount of hydrogen produced by this nanocomposite via photocatalytic water splitting is also higher as compared to non-ultrasonicated MoS$_{2}$ incorporated $\alpha$-Fe$_{2}$O$_{3}$/ZnO and $\alpha$-Fe$_{2}$O$_{3}$/ZnO nanocomposites as well as Degussa P25 titania nanoparticles. This indicates the promising potential of the incorporation of ultrasonicated MoS$_{2}$ with $\alpha$-Fe$_{2}$O$_{3}$/ZnO nanocomposite for generation of carbon-free hydrogen by water splitting. The substantial increase in the photocatalytic efficiency of $\alpha$-Fe$_{2}$O$_{3}$/ZnO after incorporation of ultrasonicated MoS$_{2}$ can be attributed to its favorable band structure, large surface to volume ratio, effective segregation and migration of photogenerated electron-hole pairs at the interface of heterojunction and the active edge sites provided by few-layer MoS$_{2}$ nanosheets.