Synergistic contributions by decreasing overpotential and enhancing electrocatalytic reduction in ONPCNRs/SWCNTs nanocomposite for highly sensitive nonenzymatic detection of hydrogen peroxide

Abstract

In this study, a novel nanocomposite material consisted of oxygen-doped, nitrogen-rich carbon nanoribbons polymer and single-walled carbon nanotubes (ONPCNRs/SWCNTs) has been facilely synthesized through simply electrostatic interaction process using poly(diallyldimethylammonium chloride) polycationic compound (PDDA). During the synthesis, the N-containing of ONPCNRs could undergo protonation to produce protonated compound under pH 6.5 condition, which could improve electrocatalytic activity of the vertically aligned N-containing ONPCNRs/SWCNTs nanocomposite due to the electron withdrawing ability of nitrogen atoms to create net positive charge on the adjacent carbon atoms in the PDDA-modified SWCNTs (PDDA/SWCNTs) plane. Meanwhile, due to the high N-doping ONPCNRs have high adsorption capacity and selectivity toward H2O2 adsorption, the combination of PDDA/SWCNTs and use of high N-doping ONPCNRs overlayer lead to an effective reduction in overpotential, enhanced Faradaic efficiencies and current densities for H2O2 reduction to H2O. As a non-enzymatic amperometric sensor, the resulting ONPCNR/SWCNTs nanocomposite-modified electrode exhibited high sensitivity and selectivity for the detection of H2O2 in the range of 1.0–500μM with a detection limit of 0.51μM (S/N=3). The results indicated that the synergetic effect with ONPCNRs improves the capability of the PDDA/SWCNTs matrix for H2O2 detection. This work demonstrated that ONPCNRs/SWCNTs nanocomposite possesses the feasibility and potential applications in sensing.