Carbon fibre cloth-supported iridium oxide/polyaniline bilayer electrode for solid-state potentiometric pH sensing
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Published Version
Supplementary Data
Date
2026-07-23
Authors
Rasel, Md
Jamal, Mamun
Padmanathan, N.
Razeeb, Kafil M.
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Published Version
Abstract
In this work, a stable solid-state potentiometric pH sensor was developed by integrating an iridium oxide/polyaniline (IrO2/PANI) bilayer onto conductive carbon fibre cloth (CFC). The resulting IrO2/PANI/CFC electrode was fabricated through sequential PANI electropolymerization followed by IrO2 electrodeposition, forming a binder free hybrid interface that combines the proton responsive conductivity of PANI with hydrated/hydroxylated proton active iridium oxide sites. Morphological, elemental, vibrational, and surface chemical analyses confirmed the successful formation of the IrO2/PANI sensing layer on the CFC substrate. The electrode exhibited a near-Nernstian response over pH 3–11, with a sensitivity of 58.4 ± 0.9 mV pH−1, good linearity and an estimated pH resolution of approximately 0.01 pH unit. During continuous pH adjustment in Britton–Robinson buffer from pH 4.5 to 11.1, the electrode maintained a comparable sensitivity of 56.8 ± 1.1 mV pH−1 without removing or washing the sensor. The electrode also showed limited interference from common cations, reversible pH tracking behaviour, acceptable short-term drift and 96.3% sensitivity retention after 45 days of repeated measurement and storage. Real-sample analysis of vinegar, orange juice, and baking powder solution showed good agreement with a commercial glass membrane pH meter. These results demonstrate the potential of IrO2/PANI/CFC as a low-cost platform for stable potentiometric pH sensing in practical sample environments.
Description
Keywords
Stable solid-state potentiometric pH sensor , [TyndallIPES] , Bilayer , Polyaniline (PANI) , Iridium oxide (IrO2) , Conductive carbon fiber cloth (CFC)
Citation
Rasel, M, Jamal, M, Padmanathan, N & Razeeb, K M 2026, 'Carbon fibre cloth-supported iridium oxide/polyaniline bilayer electrode for solid-state potentiometric pH sensing', RSC Advances, vol. 16, no. 38, pp. 42528-42539. https://doi.org/10.1039/d6ra05424b