Attapulgite‐Supported β‐Cyclodextrin‐Citric Acid Polymer for High‐Capacity Adsorption of Methylene Blue and Crystal Violet

Abstract As dye pollution increasingly threatens aquatic environments, developing efficient and renewable adsorbents has become a key research focus. In this study, an environmentally friendly composite adsorbent, β‐cyclodextrin polymer‐coated attapulgite (CDP@ATP), was successfully synthesized via in situ polymerization of β‐cyclodextrin (β‐CD) and citric acid on the surface of attapulgite (ATP), for the simultaneous removal of methylene blue (MB) and crystal violet (CV) from water. The results showed that the synergistic effect of β‐CD's host‐guest interactions, ATP's strong adsorption capacity, and the active sites of citric acid's carboxyl groups significantly enhanced CDP@ATP's adsorption performance, achieving maximum adsorption capacities of 1503.70 mg/g for MB and 1218.68 mg/g for CV. By optimizing the ATP content, the 3D network pore structure was improved, with CDP@ATP‐12.5 exhibiting the best adsorption performance. Additionally, CDP@ATP‐12.5 demonstrated excellent regeneration capabilities, maintaining removal efficiencies of over 98% for MB and 96% for CV after five adsorption‐desorption cycles. This study provides a novel adsorbent design strategy for efficiently treating complex dye wastewater, offering potential practical applications in environmental remediation.