Effect of temperature on methylene blue removal with novel 2D-Magnetism titanium carbide

Abstract

In this work, a novel two-dimensional MXene decorated with Fe3O4 (2D-MX@Fe3O4) had been successfully synthesized via an in-situ growth method. The characteristic of nanomaterials was analyzed as well as the adsorption properties toward methylene blue (cationic dyes, MB) were investigated with various temperatures. The obtained complex 2D-MX@Fe3O4 exhibited a typical 2D lamellar structure with superparamagnetic characteristic (20.3 emu·g-1). Zeta potential measurement revealed a negative charged surface of 2D-MX@Fe3O4 at neutral medium, which was favorable for cationic dye removal. Moreover, the removal process presented an excellent decolorization at high temperature with 91.93% (55 °C) compared with other lower temperatures. Adsorption isotherm indicated the removal process of MB fitted well with Freundlich isotherm model at high temperature (40 and 55 °C) whereas Langmuir isotherm for that at low temperature (25 °C). Thermodynamic study indicated an exothermic and chemisorption process for MB removal, further indicating that the increase of temperature could remarkably promote the removal capacity of 2D-MX@Fe3O4. In addition, the removal mechanism at high or low temperature was investigated by XRD, FT-IR and XPS techniques. The abundant Ti–OH groups on 2D-MX@Fe3O4 surface played a dominant role in enhancing the MB decolorization through hydrogen bonding (Ti–OH⋯N) and electrostatic attraction at high temperature system, while surface adsorption via electrostatic interaction contributed the MB removal process in the case of 25 °C.