SDS-assisted synthesis of mesoporous γ-Al2O3 with tunable surface microenvironment for enhanced adsorption beyond electrostatic interactions

： A one-step SDS-assisted synthesis method was developed to tailor the surface properties of mesoporous γ-Al 2 O 3 for enhanced adsorption of anionic dyes. Rather than relying solely on surface area, the improved adsorption performance is mainly attributed to the regulation of the surface microenvironment, which allows effective uptake even under electrostatically unfavorable conditions. Congo Red (CR) was selected as a model pollutant to evaluate adsorption performance. The modified material achieved a maximum adsorption capacity of 977 mg·g -1 , representing an increase of about 231% compared with the original value. Kinetic and isotherm results suggest that the adsorption process is closely associated with microenvironment-mediated interactions, leading to improved accessibility of active sites and more efficient interfacial interactions. Moreover, the adsorbent maintained over 95% of its initial capacity after five regeneration cycles, indicating good stability and reusability. Overall, this study demonstrates that tuning the surface microenvironment during synthesis can be an effective way to improve adsorption performance.