The use of manganese(II)-pyromellitate complex precursor for the synthesis of nanosized manganese oxides

Abstract

The increasing interest for nanosized mixed metal oxides such as spinels and spinel-based materials in last decades has been motivated by their wide applications in photocatalysis, magnetism or solar cells [1]. So far, those materials have been obtained by conventional ceramic routes that involved high temperature treatments of precursors like mixed nitrates, carbonates or hydroxides [1]. An approach based on thermal degradation of metal-organic coordination compounds has been found as a promising for the preparation of fine-dispersed spinel and spinel-based oxides, mostly because of the control over stoichiometry as well as the possibility to obtain the materials with the homogeneous distribution of metal ions [1]. As a continuation of our research relating to the design and synthesis of metal– organic coordination compounds with the aim of obtaining possibly new functional materials [2], herein we present the synthesis and characterization of new Mn(II)– dipyridylamine coordination compound with tetraanion of 1,2,4,5- benzenetetracarboxylic (pyromellitic) acid. The complex was used as a single-source precursor for the preparation of nanosized Mn2O3/Mn3O4, Mn2O3 and Mn3O4 by direct thermolysis in air atmosphere at 450, 965 and 1200 °C, respectively. The main goal of this research was to investigate the influence of decomposition temperature of the precursor on stoichiometry of the resulting nanocrystalline spinel-based manganese oxides. The structural, morphological and spectroscopic properties of these ceramic materials were also investigated.