Electrochemical evaluation of Cd2+ and Hg2+ ions in water using ZnO/Cu2ONPs/PANI modified SPCE electrode

Enyioma C. Okpara; Omolola E. Fayemi; El-Sayed M. Sherif; Pattan S. Ganesh; B.E. Kumara Swamy; Eno E. Ebenso

Sensing and Bio-Sensing Research (Feb 2022)

Electrochemical evaluation of Cd2+ and Hg2+ ions in water using ZnO/Cu2ONPs/PANI modified SPCE electrode

Enyioma C. Okpara,
Omolola E. Fayemi,
El-Sayed M. Sherif,
Pattan S. Ganesh,
B.E. Kumara Swamy,
Eno E. Ebenso

Affiliations

Enyioma C. Okpara: Department of Chemistry, School of Physical and Chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa; Material Science Innovation and Modelling (MaSIM) Research Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus) Private Bag X2046, Mmabatho 2735, South Africa
Omolola E. Fayemi: Department of Chemistry, School of Physical and Chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa; Material Science Innovation and Modelling (MaSIM) Research Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus) Private Bag X2046, Mmabatho 2735, South Africa; Corresponding author at: Department of Chemistry, School of Physical and Chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
El-Sayed M. Sherif: Center of Excellence for Research in Engineering Materials (CEREM), King Saud University, P. O. Box 800, Al-, Riyadh 11421, Saudi Arabia
Pattan S. Ganesh: Interaction Laboratory, Future Convergence Engineering, Advanced Technology Research Center, Korea University of Technology and Education, Cheonan-si 31253, Chungcheongnam-do, Republic of Korea; Corresponding author at: Department of Chemistry, School of Physical and Chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University, (Mafikeng Campus), Private Bag X2046, Mmabatho 2735, South Africa.
B.E. Kumara Swamy: Department of P.G. Studies and Research in Industrial Chemistry, Kuvempu University, Jnana Sahyadri, Shankaraghatta, 577451, Shivamogga (D), Karnataka, India
Eno E. Ebenso: Institute of Nanotechnology and Water Sustainability, College of Science, Engineering and Technology, University of South Africa, Johannesburg 1710, South Africa; Corresponding author.

Journal volume & issue: Vol. 35
p. 100476

Abstract

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Metal oxides NPs synthesized using orange peels extract (OE) and lemon peels extract (LE) and polyaniline (PANI) were used to modify the surface of screen printed carbon electrode (SPCE). The electrochemical responses of the various working electrode in potassium hexacyanoferrate (III) probe, and HCl electrolyte were evaluated using cyclic voltammetry. Integrating bimetal oxides NPs Cu2O/ZnO NPs with PANI on SPCE surface increased the electron transport properties of the sensors. The analytical performance of the SPCE treated with OE/Cu2O/ZnONPs/PANI composite, (OE/ZnO/Cu2ONPs/PANI/SPCE) and their counterpart LE/Cu2O/ZnONPs/PANI composite (LE/ZnO/Cu2ONPs/PANI/SPCE), on Cd2+, and Hg2+ ions in 0.1 M HCl electrolyte, was investigated using square voltammetry (SWV). The limits of detection at concentration range of 2.2–12.0 μM, and 0.17–1.5 μM for Cd2+ were 3.04 ppb, and 1.08 ppb, while for Hg2+ at concentration range of 2.95–11.8 μM, and 0.12–1.2 μM, the values were 5.08 ppb, and 2.72 ppb at LE/Cu2O/ZnONPs/PANI/SPC, and OE/Cu2O/ZnONPs/PANI/SPC modified electrodes respectively. The sensitivities of 108 μA/μM, and 27 μA/μM towards Hg2+, and Cd2+ were realized at OE/Cu2O/ZnONPs/PANI/SPCE, despite the narrow linear range. Relative standard deviations (RSD) at 6.55 μM concentrations for Cd2+ were 2.54%, and 6.50% for LE/Cu2O/ZnONPs/PANI/SPCE, and OE/Cu2O/ZnONPs/PANI/SPCE respectively, while the RSDs for Hg2+ at 2.94 μM concentration were 2.92%, and 4.44% using LE/Cu2O/ZnONPs/PANI/SPCE, and OE/Cu2O/ZnONPs/PANI/SPCE respectively. At OE/Cu2O/ZnONPs/PANI/SPCE, there was no significant drop in the anodic peak current for both target trace metals, in the presence of interferences, like Co2+, Mg2+, Fe2+, Ni2+, Zn2+ and Cu2+, except for 11.39% drop of the stripping peak current of Cd2+ in the presence of Zn2+. Hence, the economy of nanotechnology and sensing could profit from the recycling of biomass wastes, which are frequently poorly managed.

Published in Sensing and Bio-Sensing Research

ISSN: 2214-1804 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Engineering (General). Civil engineering (General)
Website: http://www.journals.elsevier.com/sensing-and-bio-sensing-research/

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