Facile synthesis of hierarchical Ti3C2@FeOOH nanocomposites for antimony contaminated wastewater treatment: Performance, mechanisms, reutilization, and sustainability

Designing well-behaved nanocomposites for adsorbing and removing heavy metals has been the top strategies in wastewater treatment. Herein, we report a MXene-based hierarchical nanocomposite via in-situ growth of ferric oxides (FeOOH) on the alkali Ti3C2 for efficient immobilization of Sb(III) and Sb(V) from aqueous solution. The alkalized MXene with negatively charged surface allows the formation of stable heterojunction structure between Ti3C2 and FeOOH through electrostatic self-assembly, resulting in uniformly distributed FeOOH nanoparticles onto Ti3C2 nanosheets. The Ti3C2@FeOOH nanocomposite exhibits maximum adsorption capacities at 111.50 and 93.22 mg/g for Sb(III) and Sb(V), respectively, outperforming majority of metallic-based adsorbents. DFT calculations reveal that the binding energy between Ti3C2@FeOOH and Sb(III) is higher than that of Sb(V), which agree well with the experimental results. The combination of inner-sphere complexation and electrostatic attraction are the dominant forces responsible for the removal of Sb species according to microanalysis. Moreover, the as-prepared nanocomposite presents potential applications in treating antimony contaminated wastewater with high reusability and sustainability. Interestingly, the Ti3C2@FeOOH after loading with Sb species can serve as potential electrode materials, thereby minimizing secondary pollution of waste adsorbents to the environment. This work opens new avenues for function tailoring of nano-multilayered composites towards remediation of heavy metals from water media.

Automated summary

In this study, a MXene-based hierarchical nanocomposite was reported for efficient immobilization of Sb(III) and Sb(V) from aqueous solution by in-situ growth of FeOOH on alkalized Ti3C2. The nanocomposite exhibited excellent adsorption capacities and high reusability, providing a new approach for remediation of heavy metal pollution in water.