Cellulose/silsesquioxane grafted Ti3C2Tx MXene for synergistically enhanced adsorption of uranium

The emerging two-dimensional material MXene is widely used in metal ions adsorption. However, among the various modification strategies of MXene, the study on the synergistically effect of linear natural polymer and nano-sized particles and their interaction mechanism remains unclear. In this work, polyhedral oligomeric silsesquioxane (POSS-OH) and hydroxypropyl cellulose (HPC) were grafted onto Ti3C2Tx MXene, producing chemically stable HPC/Ti3C2Tx/POSS-OH (CHMP) with adjustable interlayer space. Under the synergistic interaction, the CHMP exhibited obviously increased kinetics, high selectivity and good repeatability towards the adsorption of uranium ions (UO22+). The adsorption capacity of CHMP has been increased by 35.08%. In addition, X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscope (HR-TEM) indicated high chemical stability of CHMP. Langmuir isotherm model suggested that the adsorption mechanism of CHMP on UO22+ was the single-layer adsorption coordinated with oxygen-containing functional groups. The maximum adsorption capacity of CHMP was 307.67 mg g(-1). Furthermore, XPS and simulation results suggested that the adsorption mechanism of UO22+ was both strong coordination binding with hydroxyl groups and electrostatic interaction.