Highlights
- A novel ISM-free Pb/PbCO3 electrode is developed via in-situ electrochemical plating.
- PbCO3 nanosheet layer integrates ion recognition and signal transduction functions.
- The electrode shows near-Nernstian response, fast response time, and high selectivity.
- Successful in-situ detection of CO32− reveals diurnal variation in natural waters.
Abstract
Accurate determination of carbonate ions (CO32−) plays a pivotal role in water quality monitoring and the conservation of marine ecosystems, particularly in tracking ocean acidification processes and maintaining aquatic balance. Traditional potentiometric CO32− sensors based on all-solid-state ion selective electrodes (ASS-ISEs), face fundamental limitations such as multi-interface structural complexity, persistent water-layer formation, and high fabrication costs. In this study, we propose a novel ISM-free Pb/PbCO3 electrode for CO32− determination by electrochemically developing an in-situ PbCO3 nanosheet crystalline membrane. This solid-contact membrane integrates ion recognition and signal transduction synergistically, serving as both the ion-selective membrane and transducer, thereby eliminating interfacial instabilities inherent to traditional bilayer ASS-ISEs. This electrode exhibits a near-ideal Nernstian response slope of −32.7 ± 1.2 mV·decade−1, with a linear range from 10 to 5.15 to 10–3.13 mol·L−1 and a rapid response time of 35 s. It also demonstrates good anti-interference capabilities, with low selectivity for common anions like NO3− and SO42− enabling effective monitoring of CO32− dynamics in natural water samples. The design avoids conventional polymeric membranes, suppressing water-layer formation and enhancing mechanical stability. This study provides a cost-effective, scalable solution for in situ CO32− detection and presents a new approach to solid-contact ion sensors design through functional integration, improving real-time monitoring capabilities.
Du H., Han C., Jing H., Zhang C., Chen J., Jin S., Lv X. & Ye Y., 2025. Development of a novel ISM-free Pb/PbCO3 electrode for high-performance carbonate ion sensing. Journal of Electroanalytical Chemistry: 119383. doi: 10.1016/j.jelechem.2025.119383. Article (subscription required).
