Electroanalytical Performance of Nitrogen-Containing Tetrahedral Amorphous Carbon Thin-Film Electrodes

Abstract

Tetrahedral amorphous carbon (ta-C) consists of a mixture of sp(3)- and sp(2)-bonded carbon ranging from 60 to 40% (sp(3)/sp(3)+sp(2)) depending on the deposition conditions. The physical, chemical, and electrochemical properties depend on the sp(2)/sp(3) bonding ratio as well as the presence of incorporated impurities, such as hydrogen or nitrogen. The ability to grow ta-C at lower temperatures (25-100 °C) on a wider variety of substrates as compared to CVD diamond is an advantage of this material. Herein, we report on the structural and electrochemical properties of nitrogen-incorporated ta-C thin films (ta-C:N). The incorporation of nitrogen into the films decreases the electrical resistivity from 613 ± 60 (0 sccm N(2)) to 1.10 ± 0.07 Ω-cm (50 sccm N(2)), presumably by increasing the sp(2)-bonded carbon content and the connectedness of these domains. Similar to boron-doped diamond, these materials are characterized by a low background voltammetric current, a wide working potential window (~ 3 V), and relatively rapid electron-transfer kinetics for aqueous redox systems, including Fe(CN)(6)(-3/-4) and Ru(NH(3))(6)(+3/+2), without conventional pretreatment. Additionally, there is weak molecular adsorption of polar molecules (methylene blue) on the ta-C surface. Overall, the properties of the ta-C and ta-C:N electrodes are such that they could be excellent new choices for electroanalytical measurements.

Structure and Electroanalytical Application of Nitrogen-doped Carbon Thin Film Electrode with Lower Nitrogen Concentration

“…Swain and coworkers demonstrated that the ΔEp of Fe(CN)6 4-was dependent upon the sp 3 content of the sp 2 and sp 3 mixed carbon films. 19 On the other hand, it is well known that average roughness, surface oxygen-containing groups and wettability often influence the electron transfer rates for some redox species. However, the average roughness, O/C ratio and contact angle of N-UBM film electrodes remained almost unchanged, as summarized in Table 1.…”

“…[26][27][28][29][30] However, very few reports studied the relationship between carbon film structures, particularly about chemical bonds and electrocatalytic properties. 9,19 In this work, we studied N-UBM nanocarbon film electrodes with relatively low nitrogen concentration in terms of structural dependence of ORR. Figure 5 shows voltammograms of oxygen reduction at pure-UBM and N-UBM nanocarbon film (N = 0, 1.8, 6.4, 7.8, and 10.9 at%) electrodes.…”

Electrical and electronic properties of nitrogen doped amorphous carbon (a-CNx) thin films

“…It has been known that the radius of nitrogen atom is very close to that of carbon atom, so nitrogen is very preferable spices for doping agent with carbon. Nitrogen can be doped with carbon nanotube to increase the electronic quantum transport properties [8] energy and catalytic applications [9,10], nano-devices [11] and electro-analytical performance [12]. Nitrogen being a gaseous phase has the advantage of better control of dopant concentration in a-C films, and the incorporation of nitrogen can strongly decrease the defect density, which gives prospects on its use as a semiconductor material [13] for different energy related applications.…”

Effect of the sp2/sp3 Ratio in a Hybrid Nanocarbon Thin Film Electrode for Anodic Stripping Voltammetry Fabricated by Unbalanced Magnetron Sputtering Equipment

“…We also investigated the electron transfer rate with Fe(CN) 6 3-/4-on the basis of previous reports. 34,46,47 This is because an edge plane contributes more to the reduction of the target metals than a basal plane in ASV measurements. 48 The electron transfer rate constant (k0) on UBM (50:50) was about 4.5-times smaller than that of UBM (80:20) (Table 3).…”