Investigation of Thermolysis Processes in Chromium(III) Aromatic Carboxylates

The article examines the primary methods for obtaining carbon composite nanomaterials, with particular emphasis on thermolysis as one of the key techniques. To understand the essence of thermal decomposition processes as a method for synthesizing carbon nanomaterials, the study focuses on chromium(III) aromatic carboxylates, including chromium(III) 8-hydroxyquinolinate, benzoate, salicylate, phthalate, and p -aminobenzoate. The article considers in detail a methodology for synthesizing these chromium(III) carboxylates from commonly available inorganic chromium(III) salts under simple conditions. The thermal decomposition process is conducted in two environments (air as an oxidative medium and argon as a neutral medium) to compare the resulting products. For an in-depth study of the decomposition processes of chromium(III) carboxylates, thermal analysis methods (TGA and DSC) are employed using a Netzsch 449 Jupiter simultaneous thermal analyzer. To study the morphology and composition of the products, X-ray phase analysis, optical microscopy, scanning electron microscopy, and X-ray fluorescence microanalysis are used, employing a Rigaku Ultima IV X-ray diffractometer and a Jeol JSM-7001F scanning electron microscope equipped with an elemental microanalysis attachment. Based on the obtained results, the expected formulas of the initial chromium(III) carboxylates are calculated. The mechanisms of the processes occurring during the thermal decomposition of chromium(III) aromatic carboxylates are also proposed. To achieve a more accurate determination of the composition of the chromium(III) carboxylate synthesis products and to provide a more precise description of the thermal decomposition processes of these salts, the corresponding aromatic carboxylic acids are also subjected to thermal decomposition. The appendix of the article contains all the obtained data, providing a more precise interpretation of the results and a more detailed description of the thermal decomposition processes.