Electrocatalytic reduction of hydrogen peroxide by silver particles patterned on single-walled carbon nanotubes

Silver particles were patterned on flexible and transparent single-walled carbon nanotube (SWCNT) films using the electrochemical deposition method, and these patterned silver particles were then used as electrodes to detect hydrogen peroxide (H₂O₂). The sizes and densities of silver particles were tuned by varying the patterned design and the preparation conditions. Field emission-scanning electron microscopy revealed that the patterned silver particles were homogeneously distributed on the single-walled carbon nanotube films (AgPs-SWCNT), with an average size of 150-200 nm. X-ray diffraction patterns revealed four peaks, corresponding to a face-centered cubic silver crystal nanostructure. The AgPs-SWCNT sensor displayed a linear electrical response to H₂O₂ concentrations ranging from 0.016 mM to 18.085 mM. The detection limit and the sensitivity of the sensor were 2.76 μM and 10.92 μA mM^-1 mm^-2, respectively. Furthermore, the AgPs-SWCNT sensor was resistant to l-ascorbic acid as an interferent, indicating that it was selective for the electro-reduction of H₂O₂. In addition, the developed sensor showed a stable amperometric response to the reduction of H₂O₂ over an extended period of time.