Composite of acicular rod-like ZnO nanoparticles and semiconducting polypyrrole photoactive under visible light irradiation for methylene blue dye photodegradation

Nanoparticles of zinc oxide (ZnO) with acicular rod-like morphology were synthesized using a bicontinuous microemulsion and coated with polypyrrole (PPy), by polymerization in the presence of dioctyl sodium sulfosuccinate (AOT) surfactant with ammonium persulfate as oxidizing agent to obtain nanocomposites of ZnO/PPy. The resulting material was characterized by FTIR, Raman spectroscopy, and scanning electron microscopy. The synthesized nanocomposite consisted of ZnO nanoparticles immersed in a polypyrrole matrix with a conductivity of 6.4 × 10⁻⁶ S/cm. The synthesized nanocomposite was tested in the photodegradation of methylene blue (MB) dye under visible light irradiation resulting in photodegradation efficiency of 95.2 % after 60 min of irradiation using 3.6 g/L of nanocomposite in an aqueous solution of MB at 20 mg/L. Pseudo first-order kinetics were used to describe the photodegradation reactions.