A simple two-step solution chemistry method for synthesis of micropatterned ZnO nanorods based on metal-loaded hydrogels

High-quality micropatterning of ZnO nanorods was obtained by combining deposition of patterned ZnO seed layers, through soft lithography of metal-loaded hydrogels, with a solution method for growth of nanorods. The embossed hydrogel was photo-polymerised and thermally degraded, providing uniform, well-sintered seed layers with low surface roughness and a film thickness tunable in the range of 50-200 nm. The films were composed of small nanoparticles (20-30 nm) that were fully crystalline and had a preferred orientation along the c axis. These films acted as 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 yielded complex patterns of dense arrays of vertically aligned nanorods characterised by high lithographic quality, using inexpensive, environmentally-friendly chemicals and simple experimental apparatus. (C) 2012 Elsevier B. V. All rights reserved.