Vertical α-FeOOH nanowires grown on the carbon fiber paper as a free-standing electrode for sensitive H2O2 detection

Highly sensitive, selective, and stable hydrogen peroxide (H2O2) detection using nanozyme-based catalysts are desirable for practical applications. Herein, vertical alpha-FeOOH nanowires were successfully grown on the surface of carbon fiber paper (CFP) via a low-temperature hydrothermal procedure. The formation of vertical alpha-FeOOH nanowires is ascribed to the structure-directing role of sodium dodecyl sulfate. The resulting free-standing electrode with one-dimensional (1D) nanowires offers oriented channels for fast charge transfer, excellent electrical contact between the electrocatalyst and the current collector, and good mechanical stability and reproducibility. Thus, it can serve as an efficient electrocatalyst for the reduction and sensitive detection of H2O2. The relation of the oxidation current of H2O2 with the concentration is linear from 0.05 to 0.5 mM with a sensitivity of -0.194 mA/(mM center dot cm(2)) and a low detection limit of 18 mu M. Furthermore, the portability in the geometric tailor and easy device fabrication allow extending the general applicability of this free-standing electrode to chemical and biological sensors.