Titanium Dioxide-based Nanowells for Fabricating Nanocrystal Arrays

Templated growth of nanocrystals inside the minuscule concave features patterned on a substrate surface, or so called “nanowells” is an elegant approach to generate nanocrystal arrays. However, current methods for fabricating nanowells are generally through complex and inconvenient top-down approaches. Here we propose a simple and economic bottom-up method to fabricate TiO2-based robust and inert nanowells for growing nanocrystals. These TiO2-based nanowells are fabricated by 3 steps: 1) fabricating self-organized TiO2nanotubes by the convenient anodization method, 2) striping the fabricated nanotubes to expose the ordered nanowell array underneath, and 3) surface modifying the nanowells to adjust their surface hydrophobility. Because the morphology of the nanowells arrays can be easily tailored in Step 1 and the surface chemistry of the formed nanowells can be fine-tuned in Step 3 (e.g., the surface hydrophobicity can be easily adjusted from superhydrophobicity to superhydrophilicity), the proposed method will be well-suited for growing a wide range of nanocrystal arrays of adjustable particle sizes from various solvent systems. Moreover, the proposed TiO2-based nanowells can be used as a novel type of screening device.