Facile electrosynthesis of polyaniline|gold nanoparticle core-shell nanofiber for efficient electrocatalytic CO2 reduction

Electrochemical CO2 reduction (e-CO2RR) into valuable chemicals has been considered as a promising approach towards the carbon-neutral economy. The development of facile and scalable electrosynthetic methods to prepare electrocatalysts with high activity and selectivity is therefore of great importance. In this work, we developed a facile and scalable electrosynthetic approach to prepare core-shell-structured polyaniline|gold nanoparticles nanofiber (nanoPANI|Au) as an efficient electrocatalyst for e-CO2RR. The growth mechanism of nanoPANI|Au was thoroughly investigated, and the applied current used for the electrosynthesis of nanoPANI|Au was found to play a crucial role in determining the structure, size, and electrochemically-available surface area (ECSA) of deposited polyaniline and gold. Under optimal conditions, the prepared nanoPANI|Au exhibited a satisfactory selectivity (Faradaic efficiency: 70.0 ± 2.1%) towards the generation of CO from e-CO2RR with a high turnover frequency of 0.40 ± 0.02 s−1 and a CO-mass activity of 5.67 ± 0.31 A g−1 at a moderate overpotential of 0.59 V in NaHCO3 (0.1 M). This work opens a new avenue for the preparation of core-shell-structured conducting polymer|metal nanoparticles as the electrocatalysts for e-CO2RR.