Direct air capture (DAC) is becoming a technically feasible negative emission technology; however, the fabrication of affordable adsorbents with large CO₂ capacities, fast kinetics, and high sorption-desorption stability are of critical importance for the large-scale deployment of the DAC process. In this study, amine functionalized, aqueous miscible organic Mg_xAl-CO₃ layered double hydroxide (LDH) nanosheets are used to efficiently and rapidly capture CO₂ from ambient air. 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TRI) treatment of highly dispersed LDH nanosheets produces a sorbent exhibiting an impressive adsorption capacity of 1.05 mmol g⁻¹ at 25°C when exposed to 400 ppm CO₂, which is 30% higher than equivalent amine-functionalized SBA-15 supports. CO₂ uptake reaches 70% of this maximum capacity within 30 min and is twice as fast as supported polyamines. The highly dispersed LDH nanosheets provide excellent thermal, hydrothermal, and chemical stability, with negligible performance degradation after 50 adsorption-desorption cycles.

直接空气捕获（DAC）正在成为一种技术上可行的负排放技术；然而，制造具有大 CO ₂容量、快速动力学和高吸附-解吸稳定性的负担得起的吸附剂对于 DAC 工艺的大规模部署至关重要。在这项研究中，胺官能化的水溶性有机 Mg _x Al-CO ₃层状双氢氧化物 (LDH) 纳米片用于高效快速地从环境空气中捕获 CO ₂。高度分散的 LDH 纳米片的 3-[2-(2-氨基乙基氨基)乙基氨基]丙基-三甲氧基硅烷 (TRI) 处理产生的吸附剂在 25°C 下暴露于 400 ppm CO 时表现出令人印象深刻的 1.05 mmol g ^-1吸附容量₂，比等效的胺官能化的SBA-15载体高30%。CO ₂吸收在 30 分钟内达到该最大容量的 70%，是负载型多胺的两倍。高度分散的 LDH 纳米片具有优异的热稳定性、水热稳定性和化学稳定性，在 50 次吸附-解吸循环后性能下降可以忽略不计。