Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4

Abstract

In recent years, thermal decomposition studies of transition metal complexes with benzenepolycarboxylate ligands have become an area of a great importance due to the possibility of obtaining useful metal oxides with desirable electrical, magnetic and catalytic properties [1]. As a contrast to conventional methods for the preparation of metal oxides, such as hydrothermal or sol– gel treatment, thermolysis is faster, more efficient and environmentally friendly. Mn(II)–dipya (dipya = 2,2’-dipyridylamine) complex with tetraanion of 1,2,4,5-benzenetetracarboxylic (pyromellitic, H4pyr) acid, [Mn2(dipya)2(pyr)(H2O)2], has been prepared and characterized by elemental, spectral and microscopy analyses. Direct thermolysis of the complex up to 1200 °C in an air atmosphere yielded spinel Mn3O4 oxide material. The obtained Mn3O4 has been characterized for its structural, spectroscopic, morphological and optical properties. The possibilities of using this oxide as photocatalyst or co-photocatalyst for removing textile organic dyes, as well as inorganic pigmentary material, were also investigated and discussed.