A multifunctional anionic metal-organic framework for high proton conductivity and photoreduction of CO₂ induced by...

Metal-organic frameworks (MOFs) provide an ideal platform for loading various guests owing to their available space, and can be developed as a class of multifunctional materials. Herein, we cover the design and synthesis of two kinds of exchanged frameworks with multifunctional applications based on H₃ImDC and In(NO₃)₃·2H₂O through guest exchange inside the framework. The guest ammonium ion (NH₄⁺) and [Ru(2,2'-bipyridine)₃]²⁺ (Rubpy) are selected to exchange the dimethylammonium cation (Me₂NH₂⁺) encapsulated within In-MOF, giving birth to two kinds of new MOFs, named NH@In-MOF and Rubpy@In-MOF respectively. The proton conduction of NH@In-MOF and the CO₂ photoreduction of Rubpy@In-MOF are investigated. Under different test conditions, the proton conductive behaviors of NH@In-MOF are evaluated and the best proton conductive value can reach up to 9.81 × 10^-3 S cm^-1. Compared to the original In-MOF, Rubpy@In-MOF exhibits a significantly enhanced CO₂ photoreduction performance under a pure CO₂ atmosphere. Furthermore, its photocatalytic activity is retained even under a 10% CO₂ gas atmosphere, displaying a synergistic effect between Rubpy and In-MOF24 within Rubpy@In-MOF.