Tailoring the cap's morphology of electrodeposited gold micro-mushrooms

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Cerquido, M (Author) Other; proenca, m. p. (Author) FCUP; Dias, C (Author) Other; Leitao, DC (Author) Other; Cardoso, S (Author) Other; Freitas, PP (Author) Other; Paulo Aguiar (Author) FMUP; ventura, j. (Author) FCUP

Journal

Title: Applied Surface Science

Vol. 445

Pages: 512-518

ISSN: 0169-4332

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 6 Citations

Other information

Authenticus ID: P-00N-SQH

DOI: 10.1016/j.apsusc.2018.03.158

Abstract (EN): Ordered arrays of gold micro-mushrooms were electrodeposited inside lithographically patterned micropores with around 2 mu m in diameter and 1 mu m in depth. By using a commercial electrolytic gold bath and adjusting the deposition time (3-30 min) and potential (-0.8 to -1.3 V), one was able to tune the mushrooms' morphology. Flattened caps with large grain sizes were obtained at lower potentials and short depositions; rounded caps with smaller grains occurred at -1.0 V and longer depositions; and umbilicated caps with smoother surfaces appeared at -1.3 V. The formation of a central depression at the latter structures was ascribed to the abundant hydrogen evolution during the deposition process and to the non-uniform current density profile across the micropore. Aiming to fabricate perfectly hemispherical caps, the effect of the deposition temperature (25, 30 and 35 degrees C) on the micro-mushrooms' formation at -1.0 V was also studied, allowing the estimation of different deposition rates for the cap's height and radius. The final results provide a simple route for the fabrication of hemispherical caps by adjusting the growth conditions (time, temperature and applied potential), which is highly important for the expedite development and implementation of gold micro-mushrooms as high-performance micro-electrodes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7