Triethylamine assisted HKUST-1 formation and its electrochemical properties

HKUST-1 belongs to a group of Metal-organic framework (MOFs) materials designed by covalent bonds between copper (II) ions and benzene-1,3,5-tricarboxylate (btc3-) organic ligands. This material has a paddle-wheel structure of a secondary building unit (SBU). The properties of HKUST-1 can be improved by controlling the synthesis process such as adding the modulator especially organic base functionality agent. Triethylamine is an example of modulator that can control the synthesis process by modifying coordination structure and crystal growth. In this study, HKUST-1 was synthesized by co-precipitation process with the present of triethylamine. The morphology of the produced HKUST-1 observed by SEM where it has irregular shape that is completely different with the reported octahedral HKUST-1. The PXRD showed that HKUST-1 have the typical peaks that successfully defended the HKUST-1 framework with the highest peak at (222). The electrochemical properties were analyzed using cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). Cyclic voltammograms (CV) were carried out with potential in the range of 0.2 V - 1.0 V and scan rate was varied in the range of 5 mV/s - 100 mV/s. The stability of this material was measured at the scan rate of 20 mV/s with 10 cycles showing a fairly good stability material. Then, EIS measurements are carried out at frequency in the range of 0.1 Hz - 100 kHz to investigate the charge transfer resistance and electron transfer kinetics that occurred in HKUST-1.