Preparation of MoS2 nanoflowers with rich active sites as an efficient adsorbent for aqueous organic dyes

Abstract

In this study, molybdenum disulfide (MoS₂) was used as an adsorbent to quickly and efficiently remove Rhodamine B (RhB) from wastewater. Ultrathin layered MoS₂ nanoflowers with rich active sites were prepared via a hydrothermal method. The ultrathin layered MoS₂ nanoflowers exhibited remarkable adsorption capacity for RhB dyes, which reached 365 mg g⁻¹ within 20 min, due to the large specific BET surface area, the large amount of active sites and the intensive electrostatic attraction between the negative charges of MoS₂ nanoflowers and the RhB cationic molecules. The large BET surface area (71.7 m² g⁻¹) could provide a high number of active sites and storage centers for the RhB molecules. The adsorption behaviors were well fitted with the pseudo-second-order adsorption model and the Langmuir isotherm model. The reusability tests demonstrated that the MoS₂ nanoflowers could be reused 6 times and could retain more than 85% of their adsorption capacity. The results exhibited that the MoS₂ structure had significant adsorption capacity and could be used as an adsorbent in wastewater treatment.