Preparation of Nanosized Zero-Valent zinc (Zn^0) Immobilized on ZnO as Redox Nanocomposite for Degradation of Methyl Orange from Aqueous Solution

Introduction: In this study, nanosized zero-valent zinc (Zn^0) as a reducing agent, simultaneously synthesized and immobilized on an oxidizing agent, ZnO photocatalyst for degradation of methyl orange (MO) from the aqueous solution. Materials and Methods: The prepared redox nanocomposite (nZn^0-ZnO) was characterized by the XRD and SEM techniques. The prepared sample was separated by centrifuging. The preparation process of nZn^0-ZnO including synthesis-immobilization, washing, and drying carried out under Argon gas flow. Moreover, the effect of temperature and kinetics reaction was studied. Results: The results showed that degradation efficiency of prepared redox nanocomposite was increased compared to each ZnO nanopowder and Zn^0 under the same operational condition. The calculated activation energy for the degradation process was 4.05 KJ.mol^-1. Finally, the results showed that the degradation processes followed pseudo first order kinetic model in the basic condition by the relative deviation modulus. Conclusion: As compared to ZnO nanopowder and Zn^0, the prepared redox nanocomposite showed high degradation efficiency for the removal of methyl orange from the aqueous solution.