Hydrothermal Synthesis and Symmetrical Supercapacitor Study of 1D Ln‐H₂PDA (Ln=La and Sm) Metal‐Organic Frameworks

Abstract

Rare earth based metal-organic frameworks (RE-MOFs) are gaining importance in energy storage applications. Herein, we report the synthesis of two new RE-MOFs (Ln-H 2 PDA, Ln = La and Sm) under hydrothermal conditions using pyridine-2,6dicarboxylic acid (H 2 PDA) linker. The single-crystal analysis revealed that La-H 2 PDA MOF crystallizes into monoclinic system with P 21/c space group. Sm-H 2 PDA MOF also has the same crystal system, which is confirmed by powder X-ray diffraction pattern. These MOFs are evaluated for their charge storage behaviour using conventional 3-electrode system. Both La-H 2 PDA and Sm-H 2 PDA delivered high specific capacity of 220 C g À 1 (488 F g À 1 ) and 711 C g À 1 (1580 F g À 1 ) at a current density of 1 A g À 1 , respectively. Furthermore, a symmetric Swagelok device (Sm-H 2 PDA k Sm-H 2 PDA) has been fabricated using Sm-H 2 PDA MOF as working electrodes. The maximum energy density and power density delivered by this device are 18 Wh kg À 1 and 3744 W kg À 1 .