Preliminary Study of Modified Iron Electrodes for Ammonia Nitrogen Detection Using Voltammetry Method
Keywords:
Ammonia nitrogen, Electrochemistry, Iron, Cuprous oxideAbstract
A modified iron electrode was successfully fabricated for the electrochemical detection of ammonia nitrogen through its interaction with oxalate ions. The modification process involved immersing an iron wire in a 0.5 M CuSO₄ solution, followed by coating and subsequent treatment in a 50% H₂O₂ solution to accelerate surface oxidation. The electrochemical performance of the modified electrode was evaluated using cyclic voltammetry (CV) within a potential window of –0.4 to +0.6 V. For comparison, an unmodified iron electrode was also examined under identical conditions. The unmodified electrode exhibited no observable oxidation or reduction peaks, whereas the modified electrode demonstrated a distinct oxidation peak at +0.09 V, confirming its sensitivity toward oxalate ions. Further optimization was performed by varying the scan rate at 25, 50, 75, 100, 150, and 200 mV s⁻¹. The highest response was achieved at a scan rate of 100 mV s⁻¹, indicating optimal electrode kinetics. Calibration experiments with ammonia nitrogen concentrations ranging from 10 mM to 100 mM revealed a linear current response, described by the regression equation y = 0.0033x + 0.0591(R² = 0.9998). These results clearly demonstrate the potential of the modified iron electrode as a reliable sensor for ammonia nitrogen detection.
References
Chakraborty, U., Kaur, I., Bhanjana, G., Kumar, S., Kaur, G., Kaushik, A., & Chaudhary, G. R. (2022). Cuprous oxide nanocubes for simultaneous electrochemical detection and photocatalytic degradation of para-chloronitrobenzene. Journal of Environmental Chemical Engineering, 10(6), 108662. https://doi.org/10.1016/j.jece.2022.108662
Cui, J., Hou, J., Pan, H., & Kang, P. (2023). Self-supporting CuM LDH (M = Ni, Fe, Co) carbon cloth electrodes for selective electrochemical ammonia oxidation to nitrogen. Journal of Electroanalytical Chemistry, 940, 117502. https://doi.org/10.1016/j.jelechem.2023.117502
Duan, G. Y., Ren, Y., Tang, Y., Sun, Y. Z., Chen, Y. M., Wan, P. Y., & Yang, X. J. (2020). Improving the Reliability and Accuracy of Ammonia Quantification in Electro- and Photochemical Synthesis. ChemSusChem, 13(1), 88–96. https://doi.org/10.1002/cssc.201901623
Fu, M., Liu, M., Wu, X., Cai, Z., Zhang, X., Xi, Z., Wang, Y., Dai, C., Kang, X., Liu, Z., Miao, B., & Gao, F. (2022). A novel ternary Ag-Cu2O/Ti3C2 heterostructure with high peroxidase-like activity for on-site colorimetric detection of galactose. Sensors and Actuators B: Chemical, 369, 132343. https://doi.org/10.1016/j.snb.2022.132343
Huo, X. (n.d.). Cu2ZnSnS4/CeO2 heterojunction with excellent sensing property for ammonia nitrogen in aqueous solution—IOPscience. Retrieved September 11, 2025, from https://iopscience.iop.org/article/10.1088/1361-6641/ac0b94
Krivačić, S., Boček, Ž., Zubak, M., Kojić, V., & Kassal, P. (2024). Flexible ammonium ion-selective electrode based on inkjet-printed graphene solid contact. Talanta, 279, 126614. https://doi.org/10.1016/j.talanta.2024.126614
Li, W., Liu, J., Chen, C., Zhu, Y., Liu, N., Zhou, Y., & Chen, S. (2022). High catalytic performance non-enzymatic H2O2 sensor based on Cu2O@Cu9S5 yolk-shell nanospheres. Applied Surface Science, 587, 152766. https://doi.org/10.1016/j.apsusc.2022.152766
Liu, S., Jiang, X., Waterhouse, G. I. N., Zhang, Z.-M., & Yu, L. (2021). A Cu2O/PEDOT/graphene-modified electrode for the enzyme-free detection and quantification of glucose. Journal of Electroanalytical Chemistry, 897, 115558. https://doi.org/10.1016/j.jelechem.2021.115558
Lu, H., Hu, J., Zhang, S., Long, M., & Tang, A. (2023). Cuprous oxide and Ag modified titanium dioxide electrode for ultra-sensitive detection of ammonia nitrogen. Journal of Electroanalytical Chemistry, 949, 117842. https://doi.org/10.1016/j.jelechem.2023.117842
Mulyawati, M., Madurani, K. A., Ulfin, I., Sari, N. P., & Kurniawan, F. (2025). Development of a copper-modified iron electrode electrochemical sensor for sensitive detection of oxalic acid. Materials Chemistry and Physics, 344, 131063. https://doi.org/10.1016/j.matchemphys.2025.131063
Ramadhan, M. R., Destiny, K. D., Leoriza, M. D., Sabriena, N., Kurniawan, F., Ismail, A. I., Handayani, M., Ogata, G., Einaga, Y., & Triana, Y. (2025). Electrochemical behaviour of amodiaquine detection using boron doped diamond electrodes. International Journal of Electrochemical Science, 20(1), 100913. https://doi.org/10.1016/j.ijoes.2024.100913
Sari, N. P., Mulyawati, M., Syahputra, M. Y., Madurani, K. A., & Kurniawan, F. (2024). A Novel ultrasensitive nitrite ion detection using tungsten trioxide-modified gold electrode. Electrochimica Acta, 497, 144590. https://doi.org/10.1016/j.electacta.2024.144590
Tian, X., Yao, L., Cui, X., Zhao, R., Chen, T., Xiao, X., & Wang, Y. (2022). A two-dimensional Ti3C2TX MXene@TiO2/MoS2 heterostructure with excellent selectivity for the room temperature detection of ammonia. Journal of Materials Chemistry A, 10(10), 5505–5519. https://doi.org/10.1039/D1TA10773A
Wang, G., Gao, J., Sun, B., He, D., Zhao, C., & Suo, H. (2022). Enhanced ammonia sensitivity electrochemical sensors based on PtCu alloy nanoparticles in-situ synthesized on carbon cloth electrode. Journal of Electroanalytical Chemistry, 922, 116721. https://doi.org/10.1016/j.jelechem.2022.116721
Wang, Q., Wu, Q., Zhao, M., Lu, S., & Liang, D. (2024). Prussian blue analogue based integrated membrane electrodes for desalination and selective removal of ammonium ions in a rocking-chair capacitive deionization. Chemical Engineering Journal, 482, 148923. https://doi.org/10.1016/j.cej.2024.148923
Wang, Z., Liu, Y., Cheng, Y., Men, Y.-L., Liu, P., Zhang, L., Dai, B., & Pan, Y.-X. (2022). Fast and efficient electrocatalytic oxidation of glucose triggered by Cu2O-CuO nanoparticles supported on carbon nanotubes. Frontiers in Chemistry, 10. https://doi.org/10.3389/fchem.2022.998812
