Two 2D Metal–Organic Frameworks Based on Purine Carboxylic Acid Ligands for Photocatalytic Oxidation of Sulfides and CO<sub>2</sub> Chemical Fixation
Lin Yin, Jian-Bo Huang, Tian‐Cai Yue, Lulu Wang, Duo‐Zhi Wang
Abstract
Two two-dimensional (2D) layered metal–organic frameworks (MOFs), namely, {[Yb( L )(H 2 O) 2 NO 3 ]·2H 2 O} n (Yb-MOF) and [Er( L )(H 2 O) 3 Cl] n (Er-MOF) (H 2 L = 5-((6 H -purin-6-yl)amino)isophthalic acid), were constructed by a solvothermal method and characterized. The catalytic performance study showed that the Yb-MOF could efficiently catalyze the oxidation of sulfides to sulfoxides under 15 W light-emitting diode (LED) blue light irradiation. Electron paramagnetic resonance spectroscopy and free-radical trapping experiments demonstrated that the photocatalytic reaction process involved • O 2 –, and the corresponding mechanism was proposed. Moreover, Er-MOF exhibited good catalytic efficiency and excellent substrate tolerance in the cycloaddition reaction of CO 2, and the reaction conditions were mild. After 5 cycles, the catalytic activities of two MOFs did not significantly decrease, and the framework structures remained unchanged. Therefore, the Yb-MOF and Er-MOF were considered efficient and stable heterogeneous catalysts.