Analysis of Nanomaterials Based on Indium and Zinc Oxides by High Resolution Atomic Absorption Spectrometry with the Use of Continuous Spectral Source and Electrothermal Atomization

Abstract

The properties of nanostructured materials based on zinc and indium oxides can be modified by adding alloying elements to obtain the necessary electrical or optical properties. For example, the specificity of the chemical properties of ZnO and In2O3 for the determination of toxic gases is achieved by immobilizing Au, Ag, etc., nanoparticles on their surface. Control of the material composition plays an important role in determining the dependence between the dopant content and functional properties of the materials. The study is aimed at the development of a methodical approach to the multielement determination of catalytic dopants (Ag, Au) and matrix elements in nanostructured tin and indium oxides using the method of high resolution atomic absorption spectrometry with electrothermal atomization (ETAAS) and continuous spectral source. The matrix of the synthesized nanostructured materials is the corresponding oxide with possible oxygen deficiency due to the temperature conditions of the synthesis (300–700°C), and the content of additives (Ag, Au) is varied from 1 to 3 wt %. Optimal conditions of pyrolysis and atomization for sequential multielement analysis by the ETAAS method are determined. The optimal pyrolysis temperatures for determining Ag and Au (for both oxides), In, and Zn are 1000, 1600, 1200, and 900°C, respectively. The optimal atomization temperatures for determining Ag and Au (for nanomaterial based on indium oxide), Au (for nanomaterial based on zinc oxide), In, and Zn are 1800, 2200, 2100, 2200, and 1500°C, respectively. The accuracy of analyte determination reaches 1–4% (rel.). The correctness of the results is confirmed by inductively coupled plasma mass spectrometry. The developed method provides control of the composition of synthesized nanostructured materials for their more efficient use in photovoltaics, as well as in production of chemical sensors for detection of harmful compounds like CO, NO2, and NH3.