Synthesis, structure, fluorescence and electrochemical properties of a new Zn(ii)–organic framework constructed by a tricarboxylic acid ligand

Abstract

At present metal–organic frameworks (MOFs) provide an ideal platform for the preparation of various materials. In this work, a new efficient fluorescent sensor [Zn₃(L)(HL)(OH)(H₂O)₃]·H₂O (1) for detecting Cr₂O₇²⁻ anions has been synthesized. The luminescence intensities of compound 1 with various types of anions (I⁻, PO₄³⁻, SO₄²⁻, NO₃⁻, CO₃²⁻, Br⁻, Cr₂O₇²⁻) are investigated. The results demonstrate that compound 1 could be a potential candidate for detecting Cr₂O₇²⁻ anions with high selectivity and sensitivity. Additionally, electrocatalytic water-splitting is one of the most efficient ways to produce clean energy hydrogen, but commercially available catalysts are expensive. Hence a new material (R-C@800) has been prepared after the calcination treatment of compound 1, and it is employed as a catalyst material for the hydrogen evolution reaction (HER) in KOH media. The overpotential of R-C@800 at the current density of 10 mA cm⁻² is 395 mV. Moreover, the Tafel slope is estimated to be 191 mV dec⁻¹ by fitting the corresponding Tafel plots extracted from the polarization curves. The results show that R-C@800 is a potential HER material.