Control parameters on the fabrication of ZnO hollow nanocolumns

[EN] The present work reports on the fabrication of hollow ZnO nanocolumns by a sequential combination of electrochemical deposition, chemical attack and regeneration. Initially, ZnO nanocolumns were deposited in two different substrates, namely Fluor Tin Oxide and Indium Tin Oxide. In a further step, a statistical analysis on the most influencing control parameters in the dissolution stage to produce the hollow ZnO nanowires on the FTO substrates was carried out. The control variables considered were electrolyte concentration, dissolution time and temperature, whereas the output variable was the percentage of the hollow nanocolumns obtained. The statistical analysis consisted of a two-level factorial design of experiments on three variables, therefore involving a series of 8 experiments. An analysis of variance (ANOVA) on the results was also carried out. The results showed that all the control variables were significant, the most important being the dissolution time.This work was supported by the Spanish Government through MCINN Grant MAT2009-14625-C03-03, Generalitat Valenciana programme PROMETEO/2009/063 and European Commission through NanoCIS project FP7-PEOPLE-2010-IRSES (ref. 269279). Technical support given to the authors by the Servei de Microscopia at the Universitat Politecnica de Valencia (Spain) is greatly acknowledged.Cembrero Cil, J.; Busquets Mataix, DJ.; Rayón Encinas, E.; Pascual Guillamón, M.; Pérez Puig, MA.; Marí Soucase, B. (2013). Control parameters on the fabrication of ZnO hollow nanocolumns. Materials Science in Semiconductor Processing. 16:211-216. https://doi.org/10.1016/j.mssp.2012.04.014S2112161

Morphological dependence of hydrothermally synthesized ZnO nanowires on synthesis temperature and molar concentration

The hydrothermal synthesis behavior of ZnO nanowire (NW) on carbon nanotubes (CNTs) with respect to molar concentrations of zinc nitrate hexahydrate and hexamethylenetetramine and temperature was investigated. The ZnO NWs could be synthesized with a single-crystalline wurtzite structure and a diameter in the range of tens of nanometers. Their size does not strongly depend on the temperature, while it increases with increasing molar concentration. The NWs tend to have pyramidal shape at a growth front with increasing temperature and molar concentration probably due to enriched Zn2+ ion concentration. This demonstrates the morphological dependence of ZnO NWs on the relative rates between the decomposition of Zn precursor and subsequent oxidation of Zn to ZnO in hydrothermal synthesis