ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Catalytic and electrocatalytic activities of Fe₃O₄/CeO₂/C-dot nanocomposite

Fatemeh Honarasa, Shabnam Keshtkar, Nasrin Eskandari, and Maryam Eghbal

Department of Chemistry, Shiraz Branch, Islamic Azad University, Shiraz, Iran

E-mail: fhonarasa@gmail.com

Received: 1 September 2020  Accepted: 20 November 2020

Abstract:

Abstract

Fe₃O₄/CeO₂/C-dot nanozyme as a hybrid nanocomposite was prepared and characterized. Fe₃O₄/CeO₂/C-dot nanocomposite presents horseradish peroxidase-like catalytic activity due to the presence of triple nanozymes in the nanocomposite. The kinetic parameters of nanozymatic assay present Michaelis–Menten behavior. A colorimetric assay for determination of H₂O₂ was introduced based on the catalytic activity of Fe₃O₄/CeO₂/C-dot nanocomposite in H₂O₂/TMB system. In the presence of nanozyme, H₂O₂ reduction occurs and TMB was oxidized to ox-TMB which causes a blue color in the system. In this manner, intensity of the blue color is dependent on H₂O₂ concentration. Also, Fe₃O₄/CeO₂/C-dot nanocomposite exhibits electrocatalytic activity toward H₂O₂ reduction. Multi-walled carbon nanotube/ionic liquid paste (MWIL) electrode was modified by Fe₃O₄/CeO₂/C-dot nanocomposite which reveals higher electrocatalytic activity toward hydrogen peroxide rather than Fe₃O₄/CeO₂ and Fe₃O₄/C-dot-modified electrodes. Catalytic and electrocatalytic determination of hydrogen peroxide shows the linear ranges of 1.0 × 10^–6–5.0 × 10^–13 M and 2.0 × 10^–8 to 1.0 × 10^–6 M, respectively.

Graphic abstract

Keywords: Biomimetic; Magnetic nanocomposite; Nanozyme; Hydrogen peroxide; Peroxidase; Sensing

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01443-4

Chemical Papers 75 (6) 2371–2378 (2021)