Experimental and Theoretical Investigation of Degradation Activity of Layered Two-Dimensional MoS₂-ZnS Nanocomposites

Abstract

Commercial wastewater treatment via eco-friendly routes are highly appreciated as a sustainable solution as per the United Nation’s Sustainable Development Goal 6 (UNSDG-6). Here, we report a cost-effective and efficient route to treat wastewater by photocatalysis using sunlight. Hydrothermally-synthesized MoS2-ZnS nanocomposite is used as photocatalyst and methylene blue (MB) and rhodamine B (RhB) are used as model dyes to study the photocatalytic degradation activity. After exposure to sunlight for a period of 60 minutes, the MoS2-ZnS nanocomposite shows a degradation of 98.29 and 93.01% for MB and RhB, respectively. This enhanced photocatalytic activity of the MoS2-ZnS nanocomposite is due to its high light absorption and lower electron-hole recombination for the degradation of dyes. No harmful by-products are formed, which shows the eco-friendly nature of photocatalytic degradation of dyes in wastewater. A detailed theoretical investigation is carried out using density functional theory analysis performed for dyes and the photocatalysts in order to understand the mechanism behind the degradation. A good correlation between the calculated and experimental data is observed. This study proclaims that MoS2-ZnS nanocomposite is a cost-effective and efficient photocatalyst among other costly layered two-dimensional nanocomposites.

2D Nickel Sulfide Electrodes with Superior Electrochemical Thermal Stability along with Long Cyclic Stability for Supercapatteries

“…This claim is made on the basis of metallic nature of layered 2D MoS 2 reported with the help of XRD analysis performed at lower 2θ values in the literature. [ 27 ] Herein, we assume that the microwave‐assisted hydrothermally synthesized 2D NSN is metallic. Apart from the peaks mentioned earlier, other prominent peaks are also observed in the XRD spectrum of 2D NSN.…”

“…[ 26 ] TMDs with layered 2D architecture are highly recommended for application in supercapacitors since the 2D nanostructure exhibits peculiar characteristics such as large surface area, uniform layer structure for the easy movement of electrolyte ions in it, good electronic conductivity, etc. Nowadays, there are quite a number of research groups working on electrochemical‐charge‐storage devices using TMDs such as MoS 2 , [ 27 ] NiS 2 , [ 28 ] CoS 2 , [ 29 ] etc.…”

Rapid Synthesis of Hierarchical Cobalt Disulfide Nanostructures by Microwave-Assisted Hydrothermal Method for High Performance Supercapatteries

“…TMDs with an edge-oriented pattern having a higher density of electrochemically active sites and open structured van der Waals gaps for a large degree of interlayer diffusion/intercalation of electrolyte-ions thereby offer excellent charge storage capabilities. There are different types of TMDs like molybdenum disulfide (MoS 2 ), , tin disulfide (SnS 2 ), , tungsten disulfide (WS 2 ), , etc. that were explored in the recent past as electrode-active materials for supercapacitor applications.…”