The improved photocatalytic activity of highly expanded MoS2 under visible light emitting diodes

Abstract

Photocatalytic degradation is a promising method to remove organic pollutants from water. Photocatalysts based on two-dimensional (2D) transition metal dichalcogenides (TMDs) such as MoS₂ nanomaterials have gained tremendous popularity. This is due to their narrow band gap and high visible light absorption. Herein, a MoS₂ photocatalyst with highly expanded interlayer spaces of 1.51 nm was synthesized in the presence of Pluronic F-127 as a template by a facile one-pot hydrothermal method. This expanded MoS₂ (MF-1) managed to photodegrade 98% (2.62 × 10⁻² min⁻¹) of methylene blue (MB) dye under irradiation of 1 W visible light-emitting diode (LED) white light. The dominant performance of MF-1 is attributed to the highly expanded interlayer spacing, which exposed more active edge sites. Moreover, the formation of surface defects such as surface cracks and sulfur vacancies (Sv) facilitates the adsorption capacity and in situ generation of reactive oxygen species (ROS). The dominant ROS responsible for the photodegradation of MB is superoxide radical (˙O₂⁻). The photocatalyst shows good recyclability without deterioration even after five consecutive cycles.