Bismuth oxide photocatalytic nanostructures produced by magnetron sputtering deposition

• Published in: Thin solid films 2012-07, Vol.520 (19), p.6118-6123
• Main Authors: Sirota, B., Reyes-Cuellar, J., Kohli, P., Wang, L., McCarroll, M.E., Aouadi, S.M.
• Format: Article
• Language: English
• Subjects: Arrays; Bismuth oxide; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Deposition; Deposition by sputtering; Exact sciences and technology; Magnetron sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanowires; Other topics in nanoscale materials and structures; Photocatalysis; Physics; Quantum wires; Silicon substrates; Sputtering; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.06.001

Nanowires of bismuth oxide were grown on Si substrates by unbalanced magnetron sputtering. Deposition time for the seed layer and oxygen partial pressure were varied to optimize the morphology of the resulting array of wires. A two step process involving variable oxygen flow rates was found to create the highest density of Bi2O3 nanowires in the array. Top-view and cross-sectional SEM micrographs suggested that the resulting Bi2O3 nanowires were approximately 300nm in length with diameters of 100nm at the base and 30nm at the top. Investigation into the growth method suggests a self-catalytic process similar to vapor–liquid–solid growth. Band gap was determined by two different methods, using transmission spectroscopy and cyclic voltammetry which gave values of 2.53eV and 2.61eV respectively. Degradation experiments using rhodamine 6G display a direct relationship between nanowire density and photocatalytic results. ► Synthesis of bismuth oxide nanowires by magnetron sputtering. ► Investigate the effect of seed layer deposition time and oxygen partial pressure. ► Photocatalytic activity was shown to be correlated to nanowire density.