Enhanced ion conductivity detection utilizing superhydrophilic cauliflower-like Pt black electrodes prepared via ultrasonic electrodeposition
Dense, non-porous pure platinum electrodes in conductivity sensors suffer from bubble accumulation and surface contamination, limiting sensitivity and stability for precise marine ion detection. This study introduces a combined ultrasonic and pulse electrodeposition technique to fabricate a cauliflower-like platinum black (CF-Pt-black) layer on bare platinum substrates. The resulting electrode exhibits superhydrophilicity with a contact angle of 34.52°, a 0.7-fold reduction in impedance, and a 3.54-fold increase in charge storage capacity compared to bare Pt. Mechanical and electrochemical stability are excellent. When integrated into marine conductivity sensors, the Pt black-modified electrodes improve accuracy from 0.0025 to 0.0012 mS/cm and reduce response time by 160 s. These enhancements stem from the increased surface area and active sites provided by the porous, cauliflower-like morphology, which facilitates electrolyte adsorption and ion transfer while minimizing contaminant adhesion. The findings position CF-Pt-black as a superior candidate for high-precision ion detection, biosensing, and neural recording applications.