pH-sensitive sputtered iridium oxide films

Katsube, Teruaki; Lauks, I.; Zemel, J.N.

doi:10.1016/0250-6874(81)80060-1

Cited by 141 publications

(71 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…By comparing sensitivity, Nernst response range, ion selectivity, interference of oxidation, the iridium oxide pH electrode has been demonstrated to be the most promising one among all kinds of pH sensors. [17][18][19] The reported fabrication approaches of IrO x pH electrode include electrochemical cyclic voltammetry (CV), [19][20][21][22] electrodeposition, [23][24][25] radio frequency (RF) magnetron sputtering deposition, [26][27][28][29][30] and thermal oxidation. 14,31 Among which, the electrode produced by thermal oxidation exhibited excellent overall performance, including wide E-pH relationship range, fast response time and long term stability.…”

mentioning

confidence: 99%

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

Huang¹,

Wan²,

Jin³

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

The present work demonstrated the effects of isothermal oxidation temperature (750 • C∼870 • C) and water quenching cycle times (1∼3) on properties of IrO x pH electrodes. Property tests of the fabricated electrodes showed that electrodes developed by 800 • C isothermal heating and water quenching for 3 times (H&Q 3) had excellent near Nernst E-pH relationship, relatively faster response rate and the minimum potential drift in long-term stability test. Surface and cross-section morphologies, confocal laser scanning microscopy, electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) were employed to characterize the electrodes to explore the reason for their excellent properties. Surface morphology showed that the iridium oxide film (IROF) made by H&Q 3 at 800 • C had larger surface roughness, and well-defined homogeneous dense inner layer and loose porous outer layer. Besides, it had the minimum reaction resistance in both acid and alkaline buffers, and contained more effective compositions compared to electrodes fabricated by other conditions. Thus H&Q 3 at 800 • C was suggested to obtain a better integrated pH sensing property. Furthermore, a potential compensation method with a specially designed probe structure was proposed to correct possible errors caused by the potential drift of IrO x pH electrode in long-term pH monitoring. pH, used to reflect the grade of solvents in chemical laboratory since 1909, is an important parameter in many fields such as chemical industry, bio-industry as well as some fundamental research like electrodeposition/electrolysis and corrosion process.1-3 The glass pH electrode is a mature routine tool presenting good sensitivity, excellent stability and long life time in pH sensing. However, some of its disadvantages restrict its usage in some particular applications due to the physical nature of the glass membrane.The alternative pH electrodes include ion-sensitive field-effect transistor (ISFET) pH sensors, 4,5 optical fiber pH sensors, 6,7 hydrogel film pH sensors, [8][9][10][11][12] metal/metal oxide sensors, 13-16 etc. By comparing sensitivity, Nernst response range, ion selectivity, interference of oxidation, the iridium oxide pH electrode has been demonstrated to be the most promising one among all kinds of pH sensors. [17][18][19] The reported fabrication approaches of IrO x pH electrode include electrochemical cyclic voltammetry (CV), 19-22 electrodeposition, 23-25 radio frequency (RF) magnetron sputtering deposition, 26-30 and thermal oxidation.14,31 Among which, the electrode produced by thermal oxidation exhibited excellent overall performance, including wide E-pH relationship range, fast response time and long term stability.32-36 Wang et al. developed carbonate melt oxidation to coat Ir through the oxidation of Ir wires in a carbonate melt at 870• C for 5 hours.31 Hitchman et al. produced IrO x -electrodes by direct thermal oxidation in air at 800• C. 34 Both surface films of fabricated by the above conditions showed obvious cracks...

show abstract

mentioning

confidence: 99%

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

Huang¹,

Wan²,

Jin³

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The electrodes have Nernstian re sponse, little hysteresis during pH cycling and acceptable long-term stability [Katsubeet al, 1982], The electrodes are all sol id state and therefore preferable to glass microelectrodes whose fragility is a major short-coming for intraoral application. The sputtered iridium oxide electrode does not seem to have some of the prob lems encountered with other metal wire or metal-metal oxide electrodes that have been proposed for implantable pH sens ing applications [/ves and Janz, 1961;Edwall, 1978], i. e. there is minimal alkali me tal ion and redox interference [Katsube et al, 1982]. Other positive attributes of the present electrode material are: a wide tem perature range of Nernstian operation (0-100°C has been demonstrated); fast re sponding; low impedance -particularly important for a noise-free signal in vivo measurement; the material is etch resis tant, even in the most corrosive environ ments (boiling aqua regia for several hours), therefore long-term material sta bility in the oral environment is expected.…”

Section: Discussionmentioning

confidence: 99%

“…The Hawley appliance was completed by casting acrylic to cover the stainless steel wires, except for the 1-2 mm por tion that extended to the desired chemical sensing lo cation. Tantalum shims were coated with sputtered iridium oxide using a technique that has been report ed elsewhere in detail [Katsube et al, 1982]. Briefly, the tantalum was polished to a mirror finish, cleaned in detergent, rinsed in deionized (DI) water and placed on a water-cooled mount of a sputter chamber evacuated to 5 x I0'* 7 Torr.…”

Section: Methodsmentioning

confidence: 99%

In vitro Testing of a New System for Monitoring pH at Multiple Sites

Yankell¹,

Ram²,

Lauks³

1983

Caries Res

View full text Add to dashboard Cite

Prototype Hawley appliances have been fabricated to contain sputtered iridium oxide electrodes which extend on or into selected sites on model dentitions. No difficulty was experienced in placing or removing the appliances from the stone dental casts. In buffer solutions, the sputtered iridium oxide electrodes yielded stable Nernstian pH responses with no hysteresis. In human saliva, the steady-state response paralleled the monitoring glass electrode; however, the transient response was faster. Override and readjustment due to buffering by the saliva was recorded by the iridium oxide electrode, but not by the slower glass electrode.

show abstract

“…In voltammetry, the faradaic current is the signal while the capacitance current is a cornpoñent of the noise. For a potential pulse of amplitude AE, the capacitance current flowing as a result of electric double layer charging/discharging is given by eq (10), ic = (tE/R) exp (-t/RC) (10) where R is the total resistance of the cell, C is the double layer capacitance, and t is the time elapsed after application of the pulse. The capacitance is directly proportional to the electrode area, while for a microdisc the resistance varies inversely with electrode radius (not area) as R = p/4r, where p is the resistivity of the solution (ref.…”

Section: Microelectrodesmentioning

confidence: 99%

Current trends in electrochemical studies of nonaqueous solutions

Coetzee¹

1986

Pure and Applied Chemistry

View full text Add to dashboard Cite

-Current trends in electrochemical studies of nonaqueous solutions are discussed with the emphasis on experimental approaches judged to be particularly promising for the future development of both fundamental and applied aspects of the field of solution chemistry. Topics include recent developments in the application of potentiometric sensors to nonaqueous solutions, the potentialities of such new materials as reactively sputtered iridium oxide as hydrogen ion sensors, and the demonstrated or potential advantages of microelectrodes with diameters less than approximately 20 urn in cyclic voltamnetry and a variety of other electrochenical techniques applicable to nonaqueous solutions. The extension of electrochemical measurements to nonpolar media is emphasized. Recent developments in certain other areas such as applications of solid electrolytes and chemically modified electrodes, and studies of interfaces between immiscible solvents, are briefly discussed.

show abstract

pH-sensitive sputtered iridium oxide films

Cited by 141 publications

References 14 publications

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

In vitro Testing of a New System for Monitoring pH at Multiple Sites

Current trends in electrochemical studies of nonaqueous solutions

Contact Info

Product

Resources

About

pH-sensitive sputtered iridium oxide films

Cited by 141 publications

References 14 publications

The Effects of Cyclic Isothermal Oxidation on Ir/IrOxpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

The Effects of Cyclic Isothermal Oxidation on Ir/IrOxpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

In vitro Testing of a New System for Monitoring pH at Multiple Sites

Current trends in electrochemical studies of nonaqueous solutions

Contact Info

Product

Resources

About

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode

The Effects of Cyclic Isothermal Oxidation on Ir/IrO_xpH Electrode and a Method to Correct the Potential Drift of Metal Oxide Electrode