Low-temperature fabrication of α-Mn₂O₃ and Mn₃O₄ thin films by the spin-spray method

In this study, crystalline films of α-Mn2O3 and Mn3O4 were prepared on glass substrates at 95 °C by the spin-spray method, in which aqueous solutions containing Mn2+ and H2O2 were simultaneously sprayed. The controlled preparation of α-Mn2O3 and Mn3O4 polycrystalline films and Mn3O4 nanorod arrays can be achieved by adjusting the H2O2 concentration and pH of the reaction solution. The concentration of terephthalic acid (C8H6O4), a chemical probe for the hydroxyl radical (HO·), was used as an experimental parameter to investigate the main oxidizing agent in the spin-spray reaction. The generation of HO· was confirmed based on photoluminescence measurements and quenching tests, and the concentration of HO· was found to be a crucial factor for the phase formation in this study.