Enhanced photocatalytic activity and photoresponse of poly(3,4-ethylenedioxythiophene) nanofibers decorated with gold nanoparticle under visible light

Abstract

Conducting polymer nanostructures has been recognized as photocatlysts, a promising breakthrough in photocatalysis and other energy conversion application, such as fuel cell and battery in the near future. An efficient light harvesting hybrid nanostructures based on Poly(3,4-ethylenedioxythiophene) (PEDOT) nanofibers and gold nanoparticles (Au NPs) was prepared successfully via a one pot colloidal synthetic route. The plasmonic Au NPs (∼6 nm) are synergistically integrated on the conductive polymer nanofibers as evident from microscopic techniques. The Au/Ppy nanohybrids (NHs) demonstrate superior photocatalytic activity for organic pollutant degradation under visible light irradiation which is ∼5.6 times higher than bare polymer (kinetic constant, over 46 times higher than the traditional Au/TiO2 catalyst). The photoinduced electron transfer from PEDOT nanofibers to Au NPs at the hybrid interface may occurred via a systematic extension of conjugation from polymeric moiety due to the closer proximity of the Au NPs which enhance the charge separation. The high-coverage of Au NPs deposition on the PEDOT nanofibers further allows surface-enhanced Raman scattering to detect the analyte molecules (Dye molecules such as Rhodamine B, Methyl orange) at a concentration of 10−8 M with an enhancement factor of 104. Moreover, Au/PEDOT NHs demonstrated photoelectrochemical activity with the photo current density up to 11.2 mA cm−2, which is 65% higher than bare PEDOT under similar reaction condition. Hence, Au/PEDOT NHs can be utilize for various applications such as photocatalytic degradation of organic pollutants and as SERS substrate for simultaneous detection of the analyte molecules and water splitting.