Electrochemistry of Nanocrystalline 3C Silicon Carbide Films

• Published in: Chemistry : a European journal 2012-05, Vol.18 (21), p.6514-6519
• Main Authors: Yang, Nianjun, Zhuang, Hao, Hoffmann, René, Smirnov, Waldemar, Hees, Jakob, Jiang, Xin, Nebel, Christoph E.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Devices; Electrochemical analysis; electrochemistry; Electrode materials; Electrodes; Grafting; Ions; Nanocrystals; nanostructures; Secondary ion mass spectroscopy; Silicon carbide; surface chemistry; thin films
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201103765

Silicon carbide (SiC) films have been used frequently for high‐frequency and powder devices but have seldom been applied as the electrode material. In this paper, we have investigated the electrochemical properties of the nanocrystalline 3C‐SiC film in detail. A film with grain sizes of 5 to 20 nm shows a surface roughness of about 30 nm. The resistivity of the film is in the range of 3.5–6.2 kΩ cm. In 0.1 M H2SO4 solution, the film has a double‐layer capacitance of 30–35 μF cm−2 and a potential window of 3.0 V if an absolute current density of 0.1 mA cm−2 is defined as the threshold. Its electrochemical activity was examined by using redox probes of [Ru(NH3)6]2+/3+ and [Fe(CN)6]3−/4− in aqueous solutions and by using redox probes of quinone and ferrocene in nonaqueous solutions. Diffusion‐controlled, quasi‐reversible electrode processes were achieved in four cases. The surface chemistry of the nanocrystalline 3C‐SiC film was studied by electrochemical grafting with 4‐nitrobenzenediazonium salts. The grafting was confirmed by time‐of‐flight secondary ion mass spectroscopy. All these results confirm that the nanocrystalline 3C‐SiC film is promising for use as an electrode material. Film studies: The electrochemical properties of nanocrystalline 3C silicon carbide films have been investigated in detail for the first time. The results confirm that the film is a promising electrode material (see figure).