N-substituted CQDs impregnated by Fe3O4 heterostructure: Bifunctional catalyst for electro-catalytic and photo-catalytic detection of an environmental hazardous organic pollutant

Sasikumar Ragu; Byungki Kim; Shen-Ming Chen; Asif Ishfaque; Kwang-Mo Kang

doi:10.1016/j.chemosphere.2022.137168

N-substituted CQDs impregnated by Fe₃O₄ heterostructure: Bifunctional catalyst for electro-catalytic and photo-catalytic detection of an environmental hazardous organic pollutant

Chemosphere. 2023 Jan;311(Pt 2):137168. doi: 10.1016/j.chemosphere.2022.137168. Epub 2022 Nov 8.

Authors

Sasikumar Ragu¹, Byungki Kim², Shen-Ming Chen³, Asif Ishfaque⁴, Kwang-Mo Kang⁵

Affiliations

¹ School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan, Chungnam, 31253, Republic of Korea.
² School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan, Chungnam, 31253, Republic of Korea; Future Convergence Engineering, Korea University of Technology and Education, Cheonan, Chungnam, 31253, Republic of Korea. Electronic address: byungki.kim@koreatech.ac.kr.
³ Department of Chemical Engineering and Biotechnology, College of Engineering, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC. Electronic address: smchen78@ms15.hinet.net.
⁴ School of Mechatronics Engineering, Korea University of Technology and Education, Cheonan, Chungnam, 31253, Republic of Korea; Department of Mechanical, Mechatronics and Manufacturing Engineering, University of Engineering and Technology, Lahore, Faisalabad Campus, Faisalabad 38000, Pakistan.
⁵ Future Convergence Engineering, Korea University of Technology and Education, Cheonan, Chungnam, 31253, Republic of Korea.

PMID: 36368536
DOI: 10.1016/j.chemosphere.2022.137168

Abstract

ortho-Nitroaniline (o-NA) compounds are deemed to be a strongly toxic pollutant in nature and potentially carcinogenic; however, they are frequently utilized to synthesize dyes, pesticides, medicines, fungicides, pigments, and other organic chemicals. Their detection in an aqueous medium is fundamentally required to avoid the potential hazardous being created by these compounds. In this study, a novel sensor based on an Iron oxide (Fe₃O₄) containing highly dispersed nitrogen-doped carbon quantum dots (N-CQDs@Fe₃O₄ NFs) was demonstrated for the electrochemical detection of o-NA using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques. N-CQDs@Fe₃O₄ NFs were synthesized by hydrothermal method and studied by various analytical and spectroscopy techniques, which collectively reveal that the as-prepared composite has superior physical and chemical properties. The DPV study indicated that the o-NA sensor had a good limit of detection, linear range, and sensitivity in the range of 1.2 nm, 0.03-386.84 μM, and 36.5575 μA μM^-1 cm^-2, respectively, along with the sensor showed superior sensitivity when compared to the previously reported modified electrodes. Further, N-CQD/Fe₃O₄ NFs worked as heterogeneous catalysts for the photocatalytic reduction of o-NA to o-phenylenediamine (o-PD) in an aqueous medium. The reaction was examined under UV-Visible spectroscopy, and the complete photocatalytic reduction was observed for the N-CQD/Fe₃O₄ NFs in about 6 min with 96% as compared to other control samples; thus, authenticating the superiority of the synthesized composite in rendering the real-time applications.

Keywords: Catalytic reduction; Electrochemical detection; Environmental pollutant; Iron oxide; N-doped carbon quantum dots; O-phenylenediamine.