Electrocatalytic reduction of CO2 to CO by Gd(III) and Dy(III) complexes; and M2O3 nanoparticles (M = Gd and Dy)

•Preparation of two new Gd(III) and Dy(III) complexes and their nano-oxides.•Electrocatalytic activity of the compounds for the reduction of CO2 to CO.•The Dy(III) complex has a better electrocatalytic effect than other compounds.•An electrocatalytic cycle for the reduction of CO2 in the presence of the complexes.

Two Gd(III) and Dy(III) complexes, [M(AyGG)3(H2O)5] (AyGG = Alizarin yellow GG (NaC13H8N3O5)), have been prepared and characterized. The Gd2O3 and Dy2O3 nanoparticles were prepared by the calcination of the Gd(III) and Dy(III) complexes in air at different temperatures. The nanoparticles were characterized by FT-IR, X-ray diffraction analysis (XRD), and field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The voltammograms in the absence and presence of CO2 indicate that the Gd(III) and Dy(III) complexes and their nano-oxides can catalyze the electrochemical reduction of CO2 to CO. The results show that the Dy(III) complex has better electrocatalytic activity than other compounds.

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