Comparative study of bis-chelate M(II) complexes (M=Ni, Cu, Zn) as new heterogeneous photocatalysts for degradation of methylene blue under visible light

摘要

Three tetrahedral coordination compounds formed from Ni(II), Cu(II), and Zn(II) transition-metal ions with ON-donor, (2-aminophenol) ligand (L), were synthesized and characterized by Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy, elemental analysis, and magnetic susceptibility measurements. The magnetic properties revealed that the NiL2 and CuL2 complexes were paramagnetic while the ZnL2 complex was diamagnetic. Also, photodegradation of methylene blue as model organic pollutant by the synthesized complexes was studied based on an oxidation process under visible-light irradiation. The results showed that the photocatalytic activity of the Cu complex was greater compared with the Ni and Zn complexes, with degradation efficiency of 100, 85, and 60%, respectively, after 30min of irradiation in this condition. Thus, the Cu (bis-chelate) complex is more efficient, produces higher yield, is easily produced, and represents a more stable heterogeneous photocatalyst for degradation of organic dyes such as methylene blue.