Exfoliation of Titanium Aluminum Carbide (211 MAX Phase) to Form Nanofibers and Two-Dimensional Nanosheets and Their Application in Aqueous-Phase Cadmium Sequestration

Abstract

A green approach was adopted to exfoliate a Ti 2 AlC MAX phase. The exfoliated nanostructures (Alk-Ti 2 C fibr and Alk-Ti 2 C sheet ) with exceptional mechanical, thermal, and water stabilites, as well as abundant oxygenated active binding sites, were synthesized via a controlled hydrothermal treatment in an alkaline environment. The successful synthesis of nanofibers and sheetlike nanostructures was inferred with scanning electron microscopy and X-ray diffraction analyses. Field emission scanning electron microscopy, field-emission transmission electron microscopy, Raman spectroscopy, Brunauer−Emmett− Teller surface area, ζ-potential analyses, and X-ray photoelectron spectroscopy were utilized to investigate the material's characteristics and its structural changes after metal ion adsorption. Heavy metal ion adsorption of the synthesized nanostructures was assessed in batch tests based on Cd 2+ ion sequestration; the maximum adsorption capacity for Cd 2+ was 325.89 mg/g, which is among the highest values reported for similar materials such as graphene oxide and its derivatives. The detailed quantitative investigation confirmed the interaction of hydroxyl groups with Cd 2+ ions by electrostatic interactions, adsorption-coupled oxidation, and complex formation. Owing to their unique structure, high porosity, large specific surface area, and oxygenated functional groups, Alk-Ti 2 C sheet nanosheets were highly time-efficient for Cd 2+ removal. Moreover, Alk-Ti 2 C fibr and Alk-Ti 2 C sheet nanostructures were tested for simulated groundwater, showing that synthesized nanostructures were capable for removing Cd 2+ ions at the ppb level. The results obtained from this study suggested that nanostructures synthesized using this route could provide a new approach to prepare and exfoliate additional MAX phases for the removal of heavy metal ions and other pollutants in the environment.

Butane Dry Reforming Catalyzed by Cobalt Oxide Supported on Ti2AlC MAX Phase

“…[30] The low surface area of the Ti 2 AlC support (typically < 40 m 2 • g À 1 ) explains the low surface area of Co 3 O 4 /Ti 2 AlC, as well as the low dispersion and the large Co 3 O 4 particle size. [31] Co 3 O 4 /Al 2 O 3 and Co 3 O 4 /TiO 2 catalysts are mesoporous materials with a Brunauer-Emmett-Teller (BET) surface area of 187 and 76 m 2 • g À 1 , respectively (see Figure S3 and Table S1 in the Supporting Information for details).…”

Two-Dimensional Titanium Carbides (Ti3C2Tx) Functionalized by Poly(m-phenylenediamine) for Efficient Adsorption and Reduction of Hexavalent Chromium

“…Their unique physicochemical properties (such as a layered structure, high hydrophilic surface, and excellent electrical conductivity) endow MXenes with promising advantages in electromagnetic interference shielding [22], energy storage fields [23], and conducting thin films [24]. In recent years, MXenes have received increasing attention in the field of environment owning to their large amounts of surface negative terminations (such as -O, -OH, and -F) [25][26][27]. These negative terminations render MXenes with favorable removal capacity for cationic pollutants.…”

Carbon‐Based Composites as Anodes for Microbial Fuel Cells: Recent Advances and Challenges

“…[207] To alleviate this issue, MXene with an outstanding ion intercalation nature and conductivity can be utilized as the support. [208] The NiFe 2 O 4 -MXene/CF composite anode delivered a high power density of 1385 mW m À 2 , 5.6 times higher than the bare CF and a low internal resistance of 198 Ω (898 Ω for CF electrode). [204]…”