Back to Search
Start Over
Synthesis and electrochemical capacitance of long tungsten oxide nanorod arrays grown vertically on substrate
- Source :
- Materials Research Bulletin. 47:3612-3618
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
Abstract
- Long tungsten oxide nanorods are vertically grown on Al/W/Ti coated silicon substrates using a two-step anodization process. The first anodization of the Al film forms a mesh-like mask of anodic aluminum oxide, and the second anodization of the W film results in the formation of a buffer layer, a bottom nanorod, and a top nanorod of amorphous tungsten oxide. A pore-widening process prior to the second anodization leads to the enhancement of nanorod length above approximately 500 nm. After a heat-treatment, the tungsten oxide nanorods are crystallized to form a single crystalline structure while the buffer layer forms a polycrystalline structure. The crystalline tungsten oxide nanorods show a cyclic voltammogram retaining the quasi-rectangular shape of an electrochemically reversible faradaic redox reaction, i.e., a typical pseudocapacitive behavior. The maximum electrochemical capacitance per apparent surface area reaches approximately 2.8 mF cm −2 at the voltage scan rate of 20 mV s −1 , and the excellent cyclability of charge–discharge process is maintained up to 1000 cycles.
- Subjects :
- Horizontal scan rate
Materials science
Silicon
Anodizing
Mechanical Engineering
chemistry.chemical_element
Nanotechnology
Crystal growth
Substrate (electronics)
Condensed Matter Physics
Amorphous solid
Chemical engineering
chemistry
Mechanics of Materials
General Materials Science
Nanorod
Layer (electronics)
Subjects
Details
- ISSN :
- 00255408
- Volume :
- 47
- Database :
- OpenAIRE
- Journal :
- Materials Research Bulletin
- Accession number :
- edsair.doi...........cdea8d249ceaf70c9ae91eb2d2001452