Polyaniline-Supported Nickel Oxide Flower for Efficient Nitrite Electrochemical Detection in Water

Nada S Al-Kadhi; Mahmoud A Hefnawy; Fowzia S Alamro; Rami Adel Pashameah; Hoda A Ahmed; Shymaa S Medany

doi:10.3390/polym15071804

Polyaniline-Supported Nickel Oxide Flower for Efficient Nitrite Electrochemical Detection in Water

Polymers (Basel). 2023 Apr 6;15(7):1804. doi: 10.3390/polym15071804.

Authors

Nada S Al-Kadhi¹, Mahmoud A Hefnawy², Fowzia S Alamro¹, Rami Adel Pashameah³, Hoda A Ahmed², Shymaa S Medany²

Affiliations

¹ Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
² Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt.
³ Department of Chemistry, Faculty of Applied Science, Umm Al-Qura University, Makkah 24230, Saudi Arabia.

Abstract

A modified electrode with conducting polymer (Polyaniline) and NiO nanoflowers was prepared to detect nitrite ions in drinking water. A simple method was used to prepare the NiO nanoflower (NiOnF). Several techniques characterized the as-prepared NiOnF to determine the chemical structure and surface morphology of the NiO, such as XRD, XPS, FT-IR, and TGA. The activity of the electrode toward nitrite sensing was investigated over a wide range of pH (i.e., 2 to 10). The amperometry method was used to determine the linear detection range and limit. Accordingly, the modified electrode GC/PANI/NiOnf showed a linear range of detection at 0.1-1 µM and 1-500 µM. At the same time, the limit of detection (LOD) was 9.7 and 64 nM for low and high concentrations, respectively. Furthermore, the kinetic characteristics of nitrite, such as diffusion and transport coefficients, were investigated in various media. Moreover, the charge transfer resistance was utilized for nitrite electrooxidation in different pH values by the electrochemical impedance technique (EIS). The anti-interfering criteria of the modified surfaces were utilized in the existence of many interfering cations in water (e.g., K⁺, Na⁺, Cu²⁺, Zn²⁺, Ba²⁺, Ca²⁺, Cr²⁺, Cd²⁺, Pd²⁺). A real sample of the Nile River was spiked with nitrite to study the activity of the electrode in a real case sample (response time ~4 s). The interaction between nitrite ions and NiO{100} surface was studied using DFT calculations as a function of adsorption energy.

Keywords: NiO nano-flowers; conducting polymer; electrochemical sensor; nitrite sensing.

Grants and funding

This research was funded by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2023R85), Princess Nourah Bint Abdulrahman university, Riyadh, Saudi Arabia.