Synthesis of two polymorphic Cu-based coordination polymers of 1,2,4-benzenetricarboxylic acid along with a carbon-coated composite for the selective degradation of organic dyes.

Two polymorphic Cu-based coordination polymers (CPs) based on the ligand 1,2,4-benzenetricarboxylic acid (H 3 BTC) have been prepared via solvothermal synthesis. Each of these CPs (denoted as 1 and 2) possessed the same formula [Cu(1,2,4-H 2 BTC) 2 ]·4H 2 O but they each exhibited a distinct crystalline phase. These CPs were structurally characterized via elemental analyses, Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single crystal X-ray diffraction techniques. The title CPs display versatile structural features with 1D and 2D frameworks. Complex 1 exhibits a 2D layer, and two carboxyl groups belonging to the 1,2,4-H 2 BTC anion are deprotonated, which link the Cu(II) ions together to generate a 2D sheet. Meanwhile, complex 2 consists of a 1D chain with different coordination modes from that of 1. The influence of the aromatic polycarboxylic ligand on the structures of Cu-based complexes is discussed herein. On this basis, a 2D carbon-coated copper nanoparticle composite (Cu@C) was prepared by using the 1D Cu-based CP as a precursor. Furthermore, the selective adsorption and photocatalytic properties of Cu@C have also been investigated in detail. Two polymorphic Cu-based CPs based on 1,2,4-H 3 BTC by adjusting the ratio of organic ligands with the same formula have been synthesized and characterized. The influence of aromatic polycarboxylic ligand on the structures of Cu-based complexes has been discussed. Moreover, a 2D carbon-coated copper nanoparticle composite (Cu@C) was prepared by using the 1D Cu-CP as a precursor. Furthermore, the selective adsorption and photocatalytic properties of Cu@C have also been investigated in detail. [Display omitted] • Two polymorphic Cu-based CPs constructed with 1,2,4-H 3 BTC were synthesized. • The effect of aromatic polycarboxylic ligand on Cu-CPs had been investigated in detail. • The two CPs have high stabilities in various organic solvents. • The as-grown Cu@C was synthesized from the precursor of complex 2 by the CVD method. • The as-grown Cu@C exhibited selective adsorption and photocatalytic properties toward CR. [ABSTRACT FROM AUTHOR]