We developed a procedure for obtaining high-quality micropatterning of ZnO nanorods by combining the deposition of a patterned ZnO seed layers, obtained through soft lithography of metal-loaded hydrogels, with the hydrothermal growth of nanorods.
The embossed hydrogel is photo-polymerised and thermally degraded, providing a uniform, well-sintered seed layers with low surface roughness and a film thickness tunable in the range of 50–200 nm. The films is composed by small nanoparticles (20–30 nm) that are fully crystalline and show a preferred orientation along the c axis.
These films act as an ideal seed layers for the growth of nanorods, whose diameter could be controlled by the seeding grain size, in the range of 50–100 nm. The procedure can be used to realize complex patterns of dense arrays of vertically aligned nanorods characterised by high lithographic quality, using inexpensive, environmentally-friendly chemicals and simple experimental apparatus.
The produced complex structures of nanorods can find application in gas sensing or in energy harvesting and can be realized on several different types of substrates, including interdigited electrodes.
Related publications:
Resmini, A, U Anselmi-Tamburini, SM Emamjomeh, V Paolucci, IG Tredici, and C Cantalini. “The Influence of the Absolute Surface Area on the NO2 and H2 Gas Responses of ZnO Nanorods Prepared by Hydrothermal Growth.” Thin Solid Films, 2016.
Cittadini, M, M Sturaro, M Guglielmi, A Resmini, IG Tredici, U Anselmi-Tamburini, P Koshy, CC Sorrell, and A Martucci. “ZnO Nanorods Grown on ZnO Sol–gel Seed Films: Characteristics and Optical Gas-Sensing Properties.” Sensors and Actuators B: Chemical 213 (2015): 493–500.
A. Resmini, I. G. Tredici, C. Cantalini, L. Giancaterini, F. De Angelis, E. Rondanina, M. Patrini, D. Bajoni, and U. Anselmi-Tamburini. “A Simple All-Solution Approach to the Synthesis of Large ZnO Nanorod Networks.” J. Mater. Chem. A, January 6, 2015. doi:10.1039/C4TA05207B.
Tredici, Ilenia G., Alessandro Resmini, Frank Yaghmaie, Michael Irving, Filippo Maglia, and Umberto Anselmi-Tamburini. “A Simple Two-Step Solution Chemistry Method for Synthesis of Micropatterned ZnO Nanorods Based on Metal-Loaded Hydrogels.” Thin Solid Films 526 (2012): 22–27. doi:10.1016/j.tsf.2012.10.052.