Scalable Synthesis of Amine-Grafted Ultrafine Layered Double Hydroxide Nanosheets with Improved Carbon Dioxide Capture Capacity from Air

• Published in: ACS sustainable chemistry & engineering 2023-06, Vol.11 (25), p.9282-9287
• Main Authors: Ge, Bingyao, Chen, Chunping, Gan, Zhuozhen, Zhu, Xuancan, Miao, Yihe, Wang, Yaozu, Ge, Tianshu, O’Hare, Dermot, Wang, Ruzhu
• Format: Article
• Language: English
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.3c01183

The development of efficient adsorbents is one of the key technologies for direct air capture (DAC). Herein, a facile and scalable method to synthesize amine-functionalized layered double hydroxides (LDHs) as efficient DAC adsorbents is presented. Specifically, ultrafine and exfoliated Mg2Al–CO3 LDH nanosheets were generated within 2 min via rapid nucleation and aging followed by organic solvent treatment, and they remained exfoliated on the powders after vacuum drying. The well-dispersed LDH nanosheets were grafted with a high density of monolayered aminosilane (5.51 mmol N g–1), leading to a good CO2 adsorption capacity (0.68 mmol g–1) among amine-grafted adsorbents. Additionally, it exhibited good stability with no degradation over 200 adsorption–desorption cycles under ∼20% humid air at 25 °C.