Study of a sol-gel precursor and its evolution towards ZnO

Abstract

The processes involved in the assembly of zinc acetate dihydrate {Zn(CH3COO)2·2H2O} and ethanolamine (H2NCH2CH2OH), with or without 2-methoxyethanol as solvent, have been analysed by infrared spectra, mass spectrometry, nuclear magnetic resonance, powder X-ray diffraction and computational studies. Thermal evolution of the mixtures was characterized by thermoanalytical and structural techniques (thermogravimetry, differential thermal analysis, differential scanning calorimetry, X-ray diffraction and X-Ray photoelectron spectroscopy). Computational studies together with experiments served to thoroughly describe the precursor and its decomposition. The thermal decomposition of the mixture and its transformation into crystalline ZnO take place in a temperature range between 50 and 450 °C through different processes. With solvent, the processes need temperatures 90 oC higher with respect to the mixture without solvent, and ZnO arises at 250 ºC.