Azobenzene-based metal-organic framework incorporating persistent luminescent material LiYGeO₄:Bi³⁺ as the adsorbent for photo-responsive adsorption of CO₂

Photo-responsive adsorbents offer promising application potential because of their adaptable adsorption ability in different light situations. However, these adsorbents usually rely on continuous radiation of a light source for an extended time, which inevitably generates additional thermal effects that affect the adsorption performance. Inorganic persistent luminescent material (PLM) can exhibit excellent photo-stimulated capability and last for a long period after being irradiated with specific wavelengths of light in a short time. Herein, we fabricated a series of new composite adsorbents, JUC-PLM-n, comprising the inorganic PLM LiYGeO₄:Bi³⁺ and the azobenzene-based MOF JUC-62. The radiation at 254 nm for 10 min given to the JUC-PLM-n adsorbents with LiYGeO₄:Bi³⁺ is sufficient to produce bending inhibition of the photo-responsive ligand azobenzene group of JUC-62 for up to 6 h. The CO₂ adsorption capacity at 0 ℃ of JUC-PLM-2 decreased from 66.6 before radiation to 56.0 cm³ g⁻¹ after the 10 min radiation at 254 nm. In contrast, the CO₂ adsorption capacity of the pristine JUC-62 was almost unchanged at 254 nm.