Strategy for the improvement of electrical conductivity of a 3D Zn(ii)-coordination polymer doubly bridged by mesaconato and pyridyl-isonicotinoyl hydrazide based Schottky diode device

Abstract

Out of many stimulating research fields, the search for energy materials has become of highest priority in recent times due to issues related to sustainable development. Specific investigation in energy has focused on the coordination polymers (CPs)/metal–organic frameworks (MOFs). Due to their ordered orientation, impressive stability, and tuneable composition, MOFs are an appropriate multifunctional platform for electrochemical and photochemical energy conversion and storage. In this study, two bridging molecules, mesaconic acid (H₂mes) and pyridine-4-carboxaldehyde iso-nicotinoyl hydrazone (pcih) coordinate orthogonally to the Zn(II) metal node to construct a 3D network, [Zn(mes)(pcih)(H₂O)₂]_n (1). The formation of non-covalent interactions leads to a robust 3D super structure. A Tauc plot was used to calculate the band gap, 3.62 eV, from UV-Vis spectroscopic data, which enabled us to design a Schottky device (diode area: 9 × 10⁻⁶ m² and Richardson constant: 1.20 × 10⁶ A K⁻² m⁻²) and measure the electrical conductivity, 2.98 × 10⁻⁴ S m⁻¹ (in the dark); upon illumination, the conductivity is enhanced to 7.01 × 10⁻⁴ S m⁻¹. Furthermore, a photosensitivity value of 1.72 was observed, giving the material next-generation technological potential. It is expected that this material may provide inspiration for researchers of energy materials.