Preparation of a novel reusable 2D-MXene with flower-like LDH composite for ultra-high adsorption of congo red and doxycycline: Stability and environmental application

The development of a reusable and stable composite with strong anti-interference capability is critical for the efficient removal of emerging contaminants from wastewater. In this research, a novel recyclable two-dimensional (2D) titanium carbide (MXene) material combined with flower-like NiCo-layered double hydroxide (LDH) microspheres was successfully synthesized. Benefiting from its unique layered architecture, abundant oxidized functional groups, and high density of active binding sites, the MXene@NiCo-LDH composite exhibited exceptional adsorption performance for the removal of Congo red (CR) and doxycycline (DC) pollutants. The MXene@NiCo-LDH exhibited remarkable removal rates, reaching 98.35 % for CR and 94.66 % for DC. Furthermore, the adsorption behavior was best described by the pseudo-second-order kinetic model and fitted well to the Sips isotherm equation, showing a chemisorption-dominated mechanism on heterogeneous surfaces. The new composite displayed highest adsorption capacities of 962.66 mg/g for CR and 672.82 mg/g for DC at 313 K, outperforming most reported adsorbents. The adsorption of DC and CR through the MXene@NiCo-LDH was found to be endothermic and spontaneous. Additionally, MXene@NiCo-LDH demonstrated excellent anti-interference ability against various coexisting ions and organic compounds, while the presence of different surfactant species significantly influenced the adsorption behavior. Furthermore, the composite maintained high removal efficiencies after five consecutive adsorption–desorption cycles, with 83.11 % for CR and 81.22 % for DC, and preserved substantial adsorption capacity even after 60 days of air exposure. These results highlight the great potential of MXene@NiCo-LDH as a versatile and durable adsorbent for the treatment of dye- and antibiotic-contaminated wastewaters. • A 2D MXene-based composite was developed for the removal of Congo red and doxycycline • The maximum adsorption capacities were 962.66 mg/g for CR and 672.82 mg/g for DC • Anti-interference ability against coexisting ions and microplastics was achieved • Composite maintained 80 % efficiency after 5 cycles and stayed stable after 60 days • The new MXene@NCL performed well even under real-world wastewater conditions