A 3D oxalate-bridged [CuIIFeII] coordination polymer as molecular precursor for CuFe2O4 spinel—photocatalytic features |
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Authors: | Lidija Mol?anov Lidija Andro? Dubraja Martina Vranki? Marijana Juri? |
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Affiliation: | 1. Division of Materials Physics, Ru?er Bo?kovi? Institute, Zagreb, Croatia;2. Division of Materials Chemistry, Ru?er Bo?kovi? Institute, Zagreb, Croatia |
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Abstract: | A 3D heterometallic oxalate-bridged coordination polymer CuIIFeII2(H2O)(terpy)(C2O4)3]n (terpy = 2,2′:6′,2″-terpyridine) ( 1 ) was investigated both as photocatalyst for the organic dye removal and as a single-source precursor for the preparation of the copper ferrite (CuFe2O4) nanocrystals by thermal processing. The dual functionality of 1 was supported by the degradation of aqueous solutions of rhodamine B (RhB) and methylene blue (MB) solutions under visible (Vis) and ultraviolet (UV) light irradiation, powder X-ray diffraction data collection at room temperature, and the optical and scanning electron microscopy analyses. A close inspection of the X-ray diffraction patterns unveiled qualitative and quantitative information on the phase composition obtained after the single-source molecular precursor route to spinel oxide. By optimizing the temperature levels and setting the controlled heating rate at 6 h of holding time, the phase composition of thermal processing of 1 was evaluated—thermal treatment of 1 at 950°C for 6 h and a heating/cooling rate of 10°C min?1 resulted in the formation of solely tetragonal spinel phase of CuFe2O4, whereas the formation of both tetragonal and cubic CuFe2O4 phases was observed at 950°C by the heating rate of 30°C min?1. To obtain the high-temperature cubic CuFe2O4 oxide, compound 1 was heated and then quenched at 925°C, which led to the formation of the cubic spinel ferrite as the main crystalline oxide phase. Moreover, the photocatalytic properties of the t-CuFe2O4 spinel were investigated under the same conditions as for 1 . The optical bandgap energies were estimated from UV–Vis absorption spectra for both metal oxide and precursor powder. |
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Keywords: | bandgap photocatalysis precursors spinels thermal decomposition |
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