1 / 30

Nanowire Thinning by Electrochemical Stripping: A Route to Ultra Small Metal Wires

Explore the innovative method of Electrochemical Step Edge Decoration (ESED) to create smaller antimony and gold nanowires. Discover the process of size-selective growth through controlled etching for nanowire refinement. Case studies with results and discussion on achieving ultra-small metal wires.

gaguiar
Download Presentation

Nanowire Thinning by Electrochemical Stripping: A Route to Ultra Small Metal Wires

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nanowire "Thinning" by Kinetically Controlled Electrochemical Stripping: A New Route to Ultra Small Metal Nanowires 2005 IM-SURE Symposium Mike Thompson, R.M. Penner. Department of Chemistry. UC Irvine

  2. outline • Electrochemical Step Edge Decoration (ESED) as a method for making metal nanowires. • My mission: Make smaller Sb and Au nanowires • 3. Smaller nanowires: Results and discussion

  3. outline • Electrochemical Step Edge Decoration (ESED) as a method for making metal nanowires. • My mission: Make smaller Sb and Au nanowires • 3. Smaller nanowires: Results and discussion

  4. Electrochemical Step Edge Decoration:

  5. Our electrochemical setup…

  6. Three steps : oxidation, nucleation, and growth Sb0 Sb3+ + 3 e- Current (mA) Egrow Potential (mV vs. SCE) Sb3+ + 3 e- Sb0 Enuc Eox

  7. ESED allows for size selective growth (MoO2 wires pictured): 4 s 16 s 32 s 64 s 128 s 256 s

  8. outline • Electrochemical Step Edge Decoration (ESED) as a method for making metal nanowires. • My mission: Make smaller Sb and Au nanowires • 3. Smaller nanowires: Results and discussion

  9. A case study using antimony nanowires… 5 mM SbCl3, 0.1 M Tartaric Acid, 0.1 M Nitric Acid Current density (mA cm-2) Eox, 5s Enucl, 40 ms Egrow, 75 s Potential (mV vs. SCE)

  10. 122 nm

  11. THESE WIRES ARE TOO BIG! Antimony nanowires with diameters larger than 40 nm have no interesting properties, and thus are useless. How can we reduce the minimum size of these wires (from 120 nm to 40 nm)? The answer is simple: Use electrochemistry to slowly etch them away.

  12. Using kinetically-controlled anodic etching to make the wires smaller... Sb0 Sb3+ + 3 e- Sb3+ + 3 e- Sb0 Current (mA) Potential (mV vs. SCE)

  13. nanowire smoothing is predicted by the growth law... R= nanowire radius idep=constant deposition current Vm=molar volume n=moles of e- F= the Faraday L= nanowire length Penner, JPC-B106 (2002) 3339. Walter et al. ChemPhysChem4 (2003) 131.

  14. kinetically controlled stripping causes a constant anodic current density, thus... Thompson, Menke, Penner. in preparation

  15. outline • Electrochemical Step Edge Decoration (ESED) as a method for making metal nanowires. • My mission: Make smaller Sb and Au nanowires • 3. Smaller nanowires: Results and discussion

  16. Sb0 Sb3+ + 3 e- Sb3+ + 3 e- Sb0 Choosing the right stripping potential… Current (mA) Potential (mV vs. SCE)

  17. Stripping is extremely sensitive to the applied potential… -0.060 V -0.025 V

  18. No stripping 122 nm

  19. 250 s stripping 73 nm

  20. 500 s stripping 33 nm

  21. 33 nm

  22. Gold nanowires are interesting and difficult to make small…try stripping! Oxidation:5s @ 0.8V Nucleation: 100ms @ -1.0 V Growth: 30 s @ 0.45 V

  23. 145 nm 158 nm

  24. No stripping 145 nm 158 nm

  25. 600 s 109 nm 1200 s 66 nm

  26. THANK YOU! Thanks also to: Prof. Reg Penner Erik Menke Ben Murray Said Shokair and UROP staff Konstantin Arutyunov Funding provided by: NSF UROP EU Commission ULTRA 1-D project for the HOPG

More Related