A novel porous layered K2Ti8O17 for capturing MB and Cu(Ⅱ) in wastewater

Abstract

Appropriate structural design engineering is an effective method to achieve high adsorption performance, and optimizing the architecture to meet the desired properties remains challenging for adsorbents. Herein, a novel porous layered K2Ti8O17 (PLKTO) formed by interweaved nanowires has been successfully synthesized using MAX phase Ti2AlN and g-C3N4 as the precursors. The K2Ti8O17 nanowires consisted of numerous interconnected pores in a network-like distribution configuration, with a diameter of approximately 20 nm and a length exceeding one μm. Attractively, the PLKTO exhibited fast kinetics, large adsorption capacity, and excellent reusability toward methylene blue (MB) and Cu2+ adsorption. The maximum equilibrium adsorption capacity of MB and Cu2+ was 95.00 mg/g and 330.75 mg/g, with equilibrium times of ∼18 min and ∼25 min, respectively. The adsorption mechanism unveiled that the elimination of MB and Cu2+ was dominated by the pore-filling effect, electrostatic interaction, hydrogen bond, and surface complexation. Additionally, the PLKTO enjoyed highly selective for Cu2+ while investigating competitive adsorption behaviors in binary systems and real-world applications in various water matrices. These results indicated that the PLKTO revealed appealing application prospects for treating wastewater and pollutants and provided methodological guidance for design engineering in fabricating porous and layered structures.