Fe₃O₄ nanorods decorated on polypyrrole/reduced graphene oxide for electrochemical detection of dopamine and photocatalytic degradation of acetaminophen

The increase in the world's population has exerted tremendous pressure on the research community to solve the related health and environmental issues. Hence, it is an important and challenging task to design a multifunctional catalyst that both aids medical diagnostics and removes organic pollutants from aqueous environments. Herein, we developed iron oxide nanorods uniformly coated on the polypyrrole/reduced graphene oxide (Fe₃O₄@PPy/rGO) nanohybrids by the chemical reflux method. The optimized Fe₃O₄@PPy/rGO nanohybrids show better electrochemical detection of dopamine (DA) with a low detection limit (0.063 µM) and a better linearity range (0 to 100 µM), with a coefficient of determination of 0.994. The Fe₃O₄@PPy/rGO nanohybrids reveal an excellent DA recovery rate of 97– 98% during real sample analysis. In addition, photocatalytic studies reveal that 84% acetaminophen (ACP) degradation by Fe₃O₄@PPy/rGO nanohybrids was noticed with the persulfate. The effect of co-existing photocatalytic studies affirms that the higher ACP photodegradation rate constant of 9.13 × 10⁻⁴ M⁻¹ s⁻¹ was obtained in the presence of the Cl⁻ ion. The present work provides a new pathway for the development of a metal oxide with a conducting polymer and graphene-based catalyst for multi-functional applications for the electrochemical sensing and photodegradation of organic pollutants.