Facile preparation of MoS2 based polymer composites via mussel inspired chemistry and their high efficiency for removal of organic dyes

Abstract

Molybdenum disulfide (MoS2) is a novel type of two-dimensional nanomaterial, which has attracted great research attention for its excellent physicochemical properties and possible applications. In this work, we prepared a novel MoS2 composite (MoS2-PDOPA) through the self-polymerization of levodopa (DOPA) on the surface of MoS2 under a weak alkaline solution. The obtained samples, including pure MoS2 and MoS2-PDOPA composite were characterized by energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) analyses. The potential environmental applications of MoS2-PDOPA were evaluated by using MoS2-PDOPA as adsorbent to remove methylene blue (MB) from aqueous solution. Batch experiments were carried out to investigate the effect of various operational parameters such as contact time, initial MB concentration, solution pH and temperature on the adsorption of MB by MoS2-PDOPA. According to the adsorption kinetics, isotherms and thermodynamics analysis, the MB adsorption onto MoS2-PDOPA follows the intraparticle diffusion model and Langmuir isotherm model, and the MB adsorption process is spontaneous and endothermic. The maximum adsorption capacity of MoS2-PDOPA is calculated to be 244.03mg/g at 298K. As compared with unmodified MoS2, the adsorption capacity of MoS2-PDOPA is obviously improved. Taken together, we developed a facile method to prepare MoS2-PDOPA composites based on mussel inspired chemistry. The resultant composites could be utilized as efficient adsorbents with great potential for environmental adsorption applications.