New hydrophilic mesoporous copper (II) coordination polymers obtained from poly(ethylene terephthalate) (PET) waste for diesel removal in water

Two new hydrophilic mesoporous copper (II) coordination polymers were synthetized from poly(ethylene terephthalate) waste by the coordination reaction under solvothermal conditions in only 60 min with quantitative yields. Both polymers and their aroyl hydrazone derivates were fully characterized by NMR (1H,13C, and 1H-15N HMBC), vibrational analysis, XPS spectroscopy, and high-resolution mass spectrometry. The XPS analysis of the new polymers 3a and 3b evidenced the formation of the N → Cu and O → Cu coordination bonds and the high-resolution mass spectrometry corroborates the presence of copper atoms in their molecular structure. The textural properties of 3a and 3b were analyzed by physisorption revealing that both materials can be classified as mesoporous materials with a pore size distribution of around 14.98 nm. Furthermore, the mesoporous copper (II) coordination polymer 3a exhibits a linear behavior with a maximum adsorption capacity of 743 and 1553 mg g−1 at 0.10 and 0.20 g/L, respectively. The adsorption/desorption cycles of 3a reveal that the novel copper (II) coordination polymers obtained from poly(ethylene terephthalate) (PET) waste had a greater adsorption capacity (1553 mg g−1); showing that structural modification of this type of coordination polymers can be a remarkable tool to increase the adsorption properties through the chemical modification to more hydrophilic, porous and crystalline coordination polymers.