Electroactivity of redox probes encapsulated within sol-gel-derived silicate films

被引:62
作者
Collinson, MM [1 ]
Rausch, CG [1 ]
Voigt, A [1 ]
机构
[1] Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA
关键词
D O I
10.1021/la9701485
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The electroactivity of redox probes encapsulated within a silicate film prepared by the sol-gel process has been investigated to provide specific information about dopant stability, entrapment, and activity. Redox probes of different charges and sizes were physically doped into a sol prepared by the acid-catalyzed hydrolysis and condensation of tetramethoxysilane. The doped sols were then spin cast on pretreated glassy carbon electrodes, dried, and placed in a 0.1 M KNO3 electrolyte solution. The voltammetry of the gel-doped anionic probes (i.e., potassium ferricyanide (Fe(CN)6(3-/4-)), iridium(IV) chloride (IrCl62-/3-), potassium octacyanomolybdate(IV) (Mo(CN)(8)(4-/3-))) was Stable as the film remained in solution and/or the electrode potential continuously cycled. For the gel-doped cationic or neutral probes (i.e., ruthenium(III) hexaammine (RU(NH3)(6)(3+/2+)), ruthenium(II) tris(bipyridine) (RU(bpy)(3)(2+/3+)), ferrocenemethanol (FcCH(2)OH(0/+))), a significant reduction in the Faradaic current was observed. UV-vis spectroscopy of the electrolyte solution after electrochemical cycling of gel-encapsulated Ru(bpy)(3)(2+/3+) confirmed that the dopant leached Out of the film. The percentage of electroactive reagent was determined for Fe(CN)(6)(3-/4-) and RU(bpy)(3)(2+) and found to be 3-9% and 5-10%, respectively, consistent with entrapment in a compact, dense matrix. With the exception of the much larger RU(bpy)(3)(2+/3+), which exhibited peak-shaped voltammetry, the electrochemical behavior of the electroactive fraction of the entrapped redox probes corresponded to a surface-confined process.
引用
收藏
页码:7245 / 7251
页数:7
相关论文
共 59 条
  • [1] AHARONSON N, 1994, MATER RES SOC SYMP P, V346, P519, DOI 10.1557/PROC-346-519
  • [2] ELECTROCHEMICAL PROBING OF THE SOL-GEL XEROGEL EVOLUTION
    AUDEBERT, P
    GRIESMAR, P
    SANCHEZ, C
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 1991, 1 (04) : 699 - 700
  • [3] SOL-GEL-XEROGEL EVOLUTION INVESTIGATED BY ELECTROACTIVE PROBES IN SILICA AND TRANSITION-METAL OXIDE BASED GELS
    AUDEBERT, P
    GRIESMAR, P
    HAPIOT, P
    SANCHEZ, C
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 1992, 2 (12) : 1293 - 1300
  • [4] ELECTROCHEMICAL PROBING OF THE ACTIVITY OF GLUCOSE-OXIDASE EMBEDDED SOL-GEL MATRICES
    AUDEBERT, P
    DEMAILLE, C
    SANCHEZ, C
    [J]. CHEMISTRY OF MATERIALS, 1993, 5 (07) : 911 - 913
  • [5] THE NATURE OF THE SILICA CAGE AS REFLECTED BY SPECTRAL CHANGES AND ENHANCED PHOTOSTABILITY OF TRAPPED RHODAMINE-6G
    AVNIR, D
    LEVY, D
    REISFELD, R
    [J]. JOURNAL OF PHYSICAL CHEMISTRY, 1984, 88 (24) : 5956 - 5959
  • [6] ORGANIC-CHEMISTRY WITHIN CERAMIC MATRICES - DOPED SOL-GEL MATERIALS
    AVNIR, D
    [J]. ACCOUNTS OF CHEMICAL RESEARCH, 1995, 28 (08) : 328 - 334
  • [7] AVNIR D, 1994, SOL GEL OPTICS PROCE
  • [8] PYOVERDIN-DOPED SOL-GEL GLASS FOR THE SPECTROFLUOROMETRIC DETERMINATION OF IRON(III)
    BARRERO, JM
    CAMARA, C
    PEREZCONDE, MC
    SANJOSE, C
    FERNANDEZ, L
    [J]. ANALYST, 1995, 120 (02) : 431 - 435
  • [9] VOLTAMMETRIC EVALUATION OF THE EFFECTIVE ACIDITIES (PKA') FOR BRONSTED ACIDS IN APROTIC-SOLVENTS
    BARRETTE, WC
    JOHNSON, HW
    SAWYER, DT
    [J]. ANALYTICAL CHEMISTRY, 1984, 56 (11) : 1890 - 1898
  • [10] REVIEW OF SOL-GEL THIN-FILM FORMATION
    BRINKER, CJ
    HURD, AJ
    SCHUNK, PR
    FRYE, GC
    ASHLEY, CS
    [J]. JOURNAL OF NON-CRYSTALLINE SOLIDS, 1992, 147 : 424 - 436