Synthesis of urchin-like rutile titania carbon nanocomposites by iron-facilitated phase transformation of MXene for environmental remediation

Abstract

Self-assembling has been confirmed as an effective pathway to achieve some unique properties. The recently developed two-dimensional transition metal carbides (termed MXene) provide more potential opportunities to modify the surfaces of layered materials relative to simple graphene. Here we describe a one-step method for preparing an urchin-like rutile TiO₂–C (u-RTC) nano-composite with a high amount of (110) facets by in situ phase transformation of MXene (Ti₃C₂(OH)_0.8F_1.2) under FeCl₃ conditions. A layered anatase TiO₂–C (l-ATC) nano-composite with a high percentage of (001) facets first forms, and then it changes into u-RTC due to the Fe(III) ion induction. The u-RTC displays a high Cr(VI) adsorption capacity of ∼225 mg g⁻¹, which is higher than that of the primitive MXene (∼62 mg g⁻¹) and the l-ATC precursor (∼11 mg g⁻¹), owing to the inhibition of H₂O molecule adsorption by bridging oxo groups in terms of the first principles calculations. Apart from the fact that the finding leads to a desirable aligned oxide-carbon material, this approach may set up a new trajectory to self-assemble functional surfaces of other MXene derivatives.