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

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. A novel magnetic 2D-MXene (2D-MX@Fe3O4) nanocomposite was fabricated and the adsorption properties toward methylene blue (MB) with various temperatures were investigated. 2D-MX@Fe3O4 presented an excellent MB decolorization (91.93%) at 55 °C compared with other lower temperatures. Hydrogen bonding with electrostatic force dominated the MB removal process at 55 °C, whereas surface adsorption via electrostatic interaction was the main mechanism for 25 °C. [Display omitted] •A novel magnetic MXene nanocomposite was fabricated for MB removal.•The MB adsorption capacity was enhanced at high temperature.•The adsorption mechanism was investigated via microstructure analysis.•Enhanced MB removal was ascribed to Ti site and OH group of magnetic MXene.