Effect of magnetic field on voltammetric sensor for electrolytic concentration measurement and electrode–electrolyte interface model based on a novel geometry

Abstract

Voltammetric sensor models are widely used in electrolytic applications in industry and the laboratory. Research in these domains is enriched with data analytics tools and electrode design, which need to be revised to improve the sensitivity near the Nernst limit. Therefore, an intense demand exists for enhancing the sensitivity of conventional voltammetric sensor models with minimum alteration of design parameters. This research article focuses on the possible impact of a magnetic field in a conventional voltammetric sensor for electrolytic concentration measurement. The experimental results show a 45% increase in sensitivity with a 3%–43% increment in signal attenuation due to the magnetic field. Apart from analysing the impact of a magnetic field, this research also investigates sensors with different electrode materials and input excitation. Among different electrode materials, a sensor with Iron-Niobium is found to have maximum electrolytic sensitivity of 15.78 V mol−1 l−1 while measuring the electrolytic concentration of oxalic acid in the range of 0.001–0.01 mol l−1. Similarly, the proposed voltammetric sensor with Iron-Niobium electrodes is implemented to measure the concentration of other electrolytes with 10–130 V mol−1 l−1 sensitivity to enhance applicability. A modified electrical equivalent model with an additional inductive component is also proposed in this research work that explains the waveform dip followed by a peak overshoot due to the influence of the magnetic field. The proposed electrical equivalent model of electrode–electrolyte interface is compatible with a conventional model, which is confirmed based on the experimental observations and mathematical analysis.