To investigate conditions of silver electroless deposition on silicon (100), optical microscope, atomic force microscope (AFM) and attenuated total reflection infrared spectroscopy (ATR-FTIR) spectroscopy were used. Twenty second dipping in 0.8mM AgNO3/4.9% solution coats a silicon (100) wafer with a thin film of silver nanoparticles very well. According to AFM results, the diameter of silver particles is from 50 to 100nm. After deposition, arithmetic average of absolute values roughness (Ra) increased from ~0.7nm to ~1.2nm and the root mean square roughness (Rq) is from ~0.8nm to ~1.5nm. SCN- ions were applied to detect the existence of silver on silicon surface by ATR-FTIR spectroscopy and IR spectra demonstrate SCN- is a good adsorbent for silver metal. Patina is the general name of copper basic salts which forms green-blue film on the surface of ancient bronze architectures. Patina formation has been found on the surface of platinum or ruthenium after several scans of cyclic voltammetry in 2mM CuSO4/0.1M K2SO4, pH5 solution. Evidence implies that oxygen reduction reaction (ORR) triggers the patina formation. ORR is an important step of fuel cell process and only few sorts of noble metals like platinum can be worked as the catalyst of ORR. Mechanisms of patination involving ORR were investigated by cyclic voltammetry, optical microscope, AFM, rotating disk electrode and other experimental methods: the occurrence of ORR cause the increase of local pH on electrode, and Cu2+ ions prefer to form Cu2O by reduction. Patina forms while Cu2O is oxidizing back to Cu2+.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc12216 |
| Date | 08 1900 |
| Creators | Yang, Fan |
| Contributors | Chyan, Oliver Ming-Ren, Verbeck, Guido F. |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | Text |
| Rights | Public, Copyright, Yang, Fan, Copyright is held by the author, unless otherwise noted. All rights reserved. |
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