High-Performance pH Sensor Electrodes Based on a Hexagonal Pt Nanoparticle Array-Coated Nanoporous Alumina Membrane

Abstract

Porous anodic alumina membranes coated with Pt nanoparticles (PAAM/Pt) have been employed as pH sensor electrodes for H+ ion detection. The PAAM was designed using a two-step anodization process. Pt nanoparticles were then sputtered onto the membrane at different deposition times. The membrane’s morphological, chemical, and optical characteristics were carefully assessed following the fabrication stage using a variety of analytical techniques. The potential of the PAAM/Pt sensor electrode was investigated by measuring the potential using a simple potentiometric method. The effects of depositing Pt nanoparticles for 3–7 min on sensor electrode sensitivity were examined. The optimal potentiometric Nernstian response slope for the PAAM/Pt sensor electrode with 5 min Pt sputter coating is 56.31 mV/decade in the pH range of 3.0 to 10 at 293 K. Additionally, the PAAM/Pt sensor electrode’s stability and selectivity in various ions solutions were examined. The sensor electrode had a lifetime of more than six weeks and was kept in a normal air environment.