Impact of Various Acids and Bases on the Voltammetric Response of Platinum Group Metal Oxides

Abstract

The voltammetric response of platinum metal oxides is discussed with respect to novel pH sensors combining both miniaturization and stability. For practical applications in solutions of any kind, for example, in tap water and in domestic sewage, various interferences must be considered, such as chloride and reducing agents. This work clarifies the voltammetric behavior of RuO 2 electrodes in solutions of different pH values and ionic strengths.

Iridium and Ruthenium oxide miniature pH sensors: Long-term performance

“…The electrochemical characteristics for RUOF on Ti are shown in Figure 2b (note films on Pt delaminated when the potential was swept). Multiple peaks were observed for RUOF on Ti as reported by Chalupczok et al (21). The pH sensitivity is dominated by the Ru(III) and Ru(IV) redox couple (Eq.…”

“…If z = 1 and T = 298 K, a theoretical Nernstian sensitivity of -59 mV pH -1 is obtained. As described by Hitchman and Ramanathan (13), the formal potential (E 0 ') of pH sensitive metal oxides is highly dependent on the amount of redox couple present within the film and its degree of hydration (8,21,22). For IrOx, the stability of E 0 ' is determined by the ratio of the Ir(III) and Ir(IV)…”

Nafion Modified Titanium Nitride pH Sensor for Future Biomedical Applications

“…To address this issue, other researchers investigated the use of Nafion to modify pH electrodes, such as an IrO 2 sensor [ 18 ], and they were successful in minimizing electrode potential shift in the neutral pH range. It was demonstrated in previously published work that adding protective layers of Ta 2 O 5 [ 13 ] and Nafion [ 19 , 20 ] to a RuO 2 pH electrode lowers the redox interference and gives more accurate pH values of some samples, such as beer [ 11 ]. These modified electrodes, however, were still ineffective for samples such as wine and fresh citrus juice [ 11 ].…”

Metal Hydrogen-Bonded Organic Framework as a pH Sensor for the Detection of Strong Acids

“…As an important indicator of material property, the pH value was widely applied in various fields such as chemical engineering, chemical kinetic mechanism, and chemical industry. − In the past decades, many methods had been studied for pH detection, ranging from low precision to high precision, such as pH meters and acid–base indicators. − The pH meters had been proved to be an effective approach for pH detection because of their convenience, excellent accuracy, and high efficiency. However, its development was limited due to high cost and vulnerability. − As for the acid–base indicator, it was utilized for the detection of pH by changing color in different acidic or alkaline solutions.…”