Multifunctional poly(dopamine)-assisted synthesis of silver nano particles/carbon nanotubes nanocomposite: Toward electrochemical sensing of hydrogen peroxide with enhanced sensitivity

This study describes a facile and effective polymer-assisted route to synthesis of structurally uniform and electrochemically active single-walled carbon nanotubes–poly(dopamine)–silver particles nanocomposite (SWCNTs–PDA–AgNPs). Poly(dopamine) used here serves as a multifunctional molecule for: (1) dispersing SWCNTs into an aqueous system, tethering Ag+ precursor onto SWCNT surfaces, then (2) reducing Ag+ to Ag to eventually on-spot grow AgNPs nanoparticles onto SWCNT, and (3) promoting the nanocomposite adhesion ability. The synthetic nanocomposite was found to possess a good electrocatalytic activity toward H2O2 reduction by remarkably enhancing the current response and decreasing H2O2 reduction over potential at −0.23 V vs. Ag/AgCl, which is positive than most other electrocatalysts for H2O2 reduction. The excellent performance of H2O2 sensor can be ascribed to the synergy effects of the large surface-to-volume ratio and excellent electrocatalytic properties of SWCNTs and AgNPs, as well as the dispersing ability, reductive properties together with excellent adhesive of PDA.