Recently we demonstrated a photo-deposition method which allows positioning and patterning of hierarchical Au needle-clusters (HAuNCs) without using any surfactant or stabilizer. This green synthesis approach enables controlling the size and the geometry of deposited HAuNCs by simply altering the photocatalytic activity of the TiO₂ target, UV light intensity and irradiation time.

Fig 1. Photocatalytic Growth of Hierarchical Au Needle Clusters on Highly Active TiO₂ Thin Film.

Local irradiation of the active TiO2 thin film through a simple noncontact mask led to local patterning with extremely sharp needle-like Au nanostructures, which may find application especially in catalysis, plasmonics, and biomedical technologies (probing and manipulating biological processes).

Fig 2. Scanning electron microscopy (SEM) images of (a) periodic HAuNC arrays and (b) a single HAuNC.

Selected publications

S. Veziroglu, M.Z. Ghori, M. Kamp, L. Kienle, H.G. Rubahn, T. Strunskus, J. Fiutowski, J. Adam, F. Faupel Photocatalytic Growth of Hierarchical Au Needle Clusters on Highly Active TiO₂ Thin Film, , Adv. Mater. Interfaces. 5 (2018) 1800465.