Study on composite modification of <scp>CuAl</scp>‐<scp>LDH</scp>/<scp>HNT</scp> materials and their carbon dioxide adsorption performance

Abstract Background Among various CO 2 capture technologies, solid adsorption has become the most widely used method. In addition, organic amine modified solid adsorbents can further improve their CO 2 adsorption performance and have broad application prospects. Result CuAl‐LDH/HNT composite material was synthesized via the co‐precipitation method by using acid‐treated halloysite (HNT) as one of the substrates. Further, the xAPTES CuAl‐LDH/HNT composite adsorbent was successful synthesized by using 3‐aminopropyltriethoxysilane (APTES) as modifier. It was found that adjusting the composite ratio of CuAl‐LDH, HNT, and APTES can fully utilize the synergistic effect between materials, thereby affecting their CO 2 adsorption performance. Especially, when the ratio of CuAl‐LDH to HNT was 2:1 and the loading amount of APTES was 30 wt%, the performance of the composite material was optimal. The adsorption performance and regenerability test results of the material showed that the adsorption capacity of 30APTES‐LDH/HNT was 4.38 mmol/g after static adsorption for 24 h, and maintained over 92% regeneration efficiency after 6 cycles. By fitting the adsorption process of the material with a kinetic model, it was found that chemical adsorption was the main process, and the comparison of infrared spectra before and after adsorption also clearly showed the improved performance of the modified material. Conclusion Remarkable adsorption capacity and good recyclability suggest that synthesized APTES‐functionalized CuAl‐LDH/HNT adsorbents have high potential for CO 2 capture in industry. © 2025 Society of Chemical Industry (SCI).