Highly crystalline conductive electrodeposited films of PANI-CSA/ CoFe2O4 nanocomposites

The preparation of conductive organic films with tunable optical properties using reliable and environmently friendly methods is essential to enable many novel applications. We report the optimium conditions to prepare uniformly dense, highly crystalline and conductive films of camphor sulfonic acid protonated polyaniline (PANI) with CoFe2O4 nanoparticles (NPs) nanocomposites from aqueous solution by potentiostatic electrochemical polymerization. The prepared films have been characterized by FTIR, UV-vis spectroscopy, four-point probe method, SEM, XRD and VSM. The results reveal a bifunctional role for the CoFe2O4 NPs in lowering the pi-polaron and increasing the pi-pi* band gaps in the deposited films. Remarkably, the nanocomposite films remain highly conductive and highly crystalline even after adding 12 wt% of the CoFe2O4 NPs into the nanocomposite due to the increasing interaction of the CoFe2O4 NPs with the PANI-CSA chains. Moreover, the nanocomposite films start to exhibit some magnetic hysteresis after adding 12 wt% of the CoFe2O4 NPs. For the first time, we report two distinctive peaks at the position of the second peak in the XRD curve of PANI-CSA films indicative of the highly ordered state of the electrodeposited films. The observed properties indicate the potential use of these nanocomposite films as active materials in novel optical and electromagnetic devices.

Automated summary

Conductive and optically tunable PANI/CoFe2O4 NPs nanocomposite films were successfully prepared by potentiostatic electrochemical polymerization. The addition of CoFe2O4 NPs improved the crystallinity and conductivity of the films, and magnetic hysteresis was observed. These results indicate the potential applications of these nanocomposite films.