Electrosynthesized nanostructured polypyrrole on selective laser melted titanium scaffold

In this work, nanofiber polypyrrole (PPy) was electropolymerized on the three dimensional surface of SLM-Ti scaffold. The in situ measurement reveals that the potential variation within the 6.2 mm thickness porous SLM-Ti sample is about 20 mV resulting from the conducting property of PPy. SEM characterization shows that the diameter and thickness of PPy nanofiber fabricated at inner depth is smaller and thinner than that at the outer surface due to the lower effective overpotential and current inside porous SLM-Ti electrode. Based on the comparative electrochemical measurements, it is found that the nucleation and growth rate of PPy polymerization on 3D SLM-Ti electrode is slower than that of PPy on 2D SLM-Ti electrode. Although the nanofiber PPy film synthesized on porous scaffolds exhibits a relatively poorer reversibility and long-terms stability than that on dense sheets, there is a great potentiality to increase the electrochemical activity due to its super-high specific surface area. The work provides the fundamental perspective to study the mechanism of PPy electropolymerization on 3D SLM-Ti scaffold.