Heterointerface-Engineered Electrochemically Exfoliated MoS2/WS2 2D-Layered Nanocomposite for Efficient Visible-Light Photocatalytic Degradation of Sorafenib

TL;DR

This study develops a heterointerface-engineered MoS2/WS2 nanocomposite via electrochemical exfoliation, demonstrating high efficiency in visible-light photocatalytic degradation of the pharmaceutical pollutant sorafenib.

Contribution

It introduces a novel electrochemical exfoliation method to create ultrathin MoS2/WS2 heterostructures with enhanced photocatalytic activity for pollutant removal.

Findings

Achieved 92% degradation of sorafenib within 2 hours under visible light.

Heterostructure exhibits improved charge separation due to Type-II band alignment.

Electrochemical exfoliation produces ultrathin nanosheets with increased surface area.

Abstract

The increasing prevalence of pharmaceutical contaminants within the aquatic environment has generated considerable environmental concerns, especially regarding persistent anticancer medications like the kinase inhibitor sorafenib (SRF), which are inadequately eliminated by standard degradation methods. A heterointerface-engineered MoS2/WS2, 2D/2D layered nanocomposite was fabricated using an electrochemical exfoliation method to facilitate effective visible-light-driven photocatalytic degradation of SRF. The electrochemical exfoliation method yielded ultrathin 9.62-layer thickness MoS2/WS2 nanosheets with numerous exposed edge sites and an increased specific surface area, facilitating the development of well-interconnected van der Waals heterointerfaces. Comprehensive structural and morphological examinations utilizing field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Raman spectroscopy, and UV-visible spectroscopy validated the effective synthesis of few-layer nanosheets and their heterostructure interfaces. In contrast to the pure MoS2 and WS2 nanosheets, the MoS2/WS2 heterostructure composite demonstrated significantly enhanced photocatalytic efficacy, attaining roughly 92 % degradation of SRF within 2h under visible-light exposure. The enhanced catalytic efficiency is mainly due to the establishment of a Type-II band alignment at the MoS2/WS2 interface, facilitating effective charge separation and directional charge transfer while inhibiting electron-hole recombination. The robust interfacial interaction among the transition metal dichalcogenide layers accelerates visible-light absorption and the production of reactive oxygen species. This study illustrates that electrochemically exfoliated MoS2/WS2 heterostructure composites serve as a viable catalytic platform for the successful removal of persistent pharmaceutical pollutants.