Controlling Triboelectric Charge of MOFs by Leveraging Ligands Chemistry

Abstract

Metal-organic frameworks (MOFs) have emerged as promising materials for triboelectric nanogenerators (TENGs), but the effects of ligand choice on triboelectric charge remain underexplored. Hence, this paper demonstrates the effect of single, binary, and ternary ligands on TENG performance of cobalt/cerium-based (Co & horbar;Ce) bimetallic MOFs utilizing 2-methylimidazole (2Melm), terephthalic acid (BDC), and benzene tricarboxylic acid (BTC) as ligands. The detailed structural characterization revealed that varying ligand chemistries led to distinct MOF features affecting TENG performance. Single ligand bimetallic MOFs (designated as CoCe-2MeIm, CoCe-BDC, CoCe-BTC) has lower performance than binary ligand (designated as CoCe-2MeIm-BDC, CoCe-2MeIm-BTC, CoCe-BDC-BTC) and ternary ligand MOFs (designated as CoCe-2MeIm-BDC-BTC). Among all, the binary ligand MOF, CoCe-2MeIm-BTC, shows the best results (598 V, 26.7 mu A) due to the combined effect of imidazole ring and (& horbar;COO & horbar;) groups. This is attributed to lone pairs on nitrogen atoms and a delocalized pi-electron system in imidazole system in this material. CoCe-BTC has the lowest results (31 V, 3.2 mu A) due to the bulkier nature of the electron-withdrawing (& horbar;COO & horbar;) groups and their impact on the pi-electron system of the benzene ring. This study showcases the potential of ligand chemistry manipulation to control triboelectric charge and thereby enhance MOF-based TENG performance. To enhance metal-organic framework (MOF)-based triboelectric nanogenerator (TENG) performance, it explored the effects of single, binary, and ternary ligands for triboelectric charge. Especially, cobalt/cerium-based (Co & horbar;Ce) bimetallic MOFs utilizing 2-methylimidazole (2Melm), terephthalic acid (BDC), and benzene tricarboxylic acid (BTC) ligands are considered, and the binary ligand MOF (CoCe-2MeIm-BTC) shows the best results (598 V, 26.7 mu A) due to the combined effect of imidazole ring and (& horbar;COO & horbar;) groups. Hence, these results can boost TENG performance while keeping stable temperature and humidity characteristics. image