Primary Corrosion Processes for Polymer-Embedded Free-Standing or Substrate-Supported Silicon Microwire Arrays in Aqueous Alkaline Electrolytes
Abstract
Solar fuel devices have shown promise as a sustainable source of chemical fuels. However, long-term stability of light absorbing materials remains a substantial barrier to practical devices. Herein, multiple corrosion pathways in 1 M KOH(aq) have been defined for TiO₂-protected Si microwire arrays in a polymer membrane either attached to a substrate or free-standing. Top-down corrosion was observed in both morphologies through defects in the TiO₂ coating. For the substrate-based samples, bottom-up corrosion was observed through the substrate and up the adjacent wires. In the free-standing samples, uniform bottom-up corrosion was observed through the membrane with all wire material corroded within 10 days of immersion in the dark in 1 M KOH(aq).
Additional Information
© 2021 American Chemical Society. Received: October 27, 2020; Revised: December 18, 2020; Published: January 6, 2021. This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy-Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993. We gratefully acknowledge the critical support and infrastructure provided for this work by the Kavli Nanoscience Institute at Caltech. Author Contributions: K.M.K. and P.K. conceived the idea and designed the study. P.K. fabricated the microwire arrays and contributed to figure design. K.M.K. performed the corrosion experiments, optical and SEM characterization, and wrote the text. M.C.A. performed the FIB studies and contributed substantially to the intellectual understanding of the corrosion process. K.M.P. wrote the Matlab code used to analyze the optical images and generate statistics. The authors declare no competing financial interest.Attached Files
Supplemental Material - nl0c04298_si_001.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:52348dbfd0438c844c6aae7f6ab55a0e
|
232.7 kB | Preview Download |
Additional details
- Eprint ID
- 107416
- Resolver ID
- CaltechAUTHORS:20210112-091401361
- DE-SC0004993
- Department of Energy (DOE)
- Created
-
2021-01-12Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP, Kavli Nanoscience Institute