Integrated Soft Porosity and Electrical Properties of Conductive‐on‐Insulating Metal‐Organic Framework Nanocrystals
Ming‐Shui Yao, Ken‐ichi Otake, Jia‐Jia Zheng, Masahiko Tsujimoto, Yifan Gu, Zheng Lu, Ping Wang, Mohana Shivanna, Mickaële Bonneau, Tomoyuki Koganezawa, Tetsuo Honma, Hirotaka Ashitani, Shogo Kawaguchi, Yoshiki Kubota, Susumu Kitagawa
Abstract
Abstract A one‐stone, two‐bird method to integrate the soft porosity and electrical properties of distinct metal–organic frameworks (MOFs) into a single material involves the design of conductive‐on‐insulating MOF ( c MOF‐on‐ i MOF) heterostructures that allow for direct electrical control. Herein, we report the synthesis of c MOF‐on‐ i MOF heterostructures using a seeded layer‐by‐layer method, in which the sorptive i MOF core is combined with chemiresistive c MOF shells. The resulting c MOF‐on‐ i MOF heterostructures exhibit enhanced selective sorption of CO 2 compared to the pristine i MOF (298 K, 1 bar, S from 15.4 of ZIF‐7 to 43.2–152.8). This enhancement is attributed to the porous interface formed by the hybridization of both frameworks at the molecular level. Furthermore, owing to the flexible structure of the i MOF core, the c MOF‐on‐ i MOF heterostructures with semiconductive soft porous interfaces demonstrated high flexibility in sensing and electrical “shape memory” toward acetone and CO 2 . This behavior was observed through the guest‐induced structural changes of the i MOF core, as revealed by the operando synchrotron grazing incidence wide‐angle X‐ray scattering measurements.