Mixed metal oxide decorated polypyrrole nanocomposites for multifunctional applications

Mixed metal oxide nanocomposites of TiO2, ZnO, and CuO were synthesized by the improved Sol-gel method. Polymerization of polypyrrole (PPy) was carried out by chemical oxidative technique. In situ technique was used to synthesize mixed metal/PPy nanocomposites. The photocatalytic, antibacterial, anticorrosive, electrical, and magnetic properties of polymeric nanocomposites were investigated. The photosensitivity of polymeric nano-composites was examined for degrading methylene blue dye in visible light. The variation in pH and Chemical Oxygen Demand (COD) with the degradation time of dye was followed. pH increases and COD decreases with an increase in photodegradation of dye with time. The antibacterial properties of polymeric nanocomposites and metal oxide nanocomposites were investigated against E. coli and B. subtilis and compared with 06 antibiotics (Hexa disk). The optical band gap of metal oxide nanocomposites, PPy, and PPy/mixed metal oxide nano-composites was investigated by Tauc plots. The photocatalytic degradation of methylene blue follows pseudo 1st-order kinetics with a velocity constant of 0.0685 min  1. The mixed metal/PPy nanocomposites show 80.1 +/- 0.2 % corrosion inhibition efficiency. The maximum zone of inhibition shown by mixed metal nanocomposites was 12.5 +/- 0.1 mm against E. coli. The mixed metal/PPy nanocomposites (100 ppm) degrade 92 % of the methylene blue dye after 90 min. of visible light exposure. The magnetic properties show a high degree of magnetization retention in polymeric nanocomposites. Mixed metal/PPy nanocomposites show very good photocatalytic, antibacterial, anticorrosive, electrical, and magnetic properties and hence act as advanced functional nano-materials for multifunctional applications.