1
|
Turley JP, Romer F, Trudeau ML, Dias ML, Smith ME, Hanna JV, Antonelli DM. Proton conductivity of naphthalene sulfonate formaldehyde resin-doped mesoporous niobium and tantalum oxide composites. CHEMSUSCHEM 2015; 8:301-309. [PMID: 25209169 DOI: 10.1002/cssc.201402546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Proton conductivity in a series of mesoporous niobium and tantalum metal oxide (mX2 O5 ) composites of naphthalene sulfonic acid formaldehyde resin (NSF) that are resistant to moisture loss at temperatures greater than 50 °C is reported. The investigation focuses on the effect to proton conductivity by changing pore size and metal in the mesostructure of the mX2 O5 system and thus, a series of mX2 O5 -NSF composites were synthesized with C6 , C12 , and C18 templates. These were characterized by XRD, thermogravimetric analysis, nitrogen adsorption, and scanning TEM and then studied using impedance spectroscopy to establish proton conductivity values at various temperatures ranging from 25 to 150 °C. The most promising sample displayed a conductivity of 21.96 mS cm(-1) at 100 °C, surpassing the literature value for Nafion 117 (ca. 8 mS cm(-1) ). (1) H and (13) C solid state NMR studies the mX2 O5 -NSF composites demonstrate that the oligomeric nature of the NSF is preserved while in contact with the mX2 O5 surface, thus facilitating conductivity.
Collapse
Affiliation(s)
- Jonathan P Turley
- Sustainable Environment Research Centre, University of South Wales, Pontypridd, CF37 4BD (UK)
| | | | | | | | | | | | | |
Collapse
|
2
|
Malik S, Tripathi CC. Thin Film Deposition by Langmuir Blodgett Technique for Gas Sensing Applications. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/jsemat.2013.33031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
3
|
Snowden ME, Edwards MA, Rudd NC, Macpherson JV, Unwin PR. Intrinsic electrochemical activity of single walled carbon nanotube–Nafion assemblies. Phys Chem Chem Phys 2013; 15:5030-8. [DOI: 10.1039/c3cp44538k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
4
|
Fish JS, Li CP, Fehribach JD, Wolden CA, O’Hayre R, Bunge AL, Goodyer CE. Poisson–Boltzmann model of space charge layer effects on conductivity in randomly distributed nanoionic composites. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.07.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
5
|
|
6
|
Vuorema A, Shariki S, Sillanpää M, Thielemans W, Nelson GW, Foord JS, Dale SEC, Bending S, Marken F. Enhanced TiO2 surface electrochemistry with carbonised layer-by-layer cellulose-PDDA composite films. Phys Chem Chem Phys 2011; 13:9857-62. [DOI: 10.1039/c1cp20532c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
7
|
A biocompatible nano TiO2/nafion composite modified glassy carbon electrode for the detection of fenitrothion. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2010.10.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
8
|
Devadoss A, Spehar-Délèze AM, Tanner DA, Bertoncello P, Marthi R, Keyes TE, Forster RJ. Enhanced electrochemiluminescence and charge transport through films of metallopolymer-gold nanoparticle composites. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:2130-2135. [PMID: 19928861 DOI: 10.1021/la902676p] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Water-soluble 4-(dimethylamino) pyridine (DMAP) stabilized gold nanoparticles (DMAP-AuNP) were synthesized by ligand exchange and phase transfer (toluene/water). The DMAP-AuNPs are positively charged with the core diameter of 4 +/- 1 nm. Metallopolymer-gold nanocomposites were prepared by mixing gold nanoparticles and [Ru(bpy)(2)PVP(10)](ClO(4))(2), in water at different mole ratios; bpy is 2,2'-bipyridyl and PVP is poly (4-vinylpyridine). The photoluminescence emission intensity of the metallopolymer decreases with increasing AuNP loading and approximately 57% of the emission intensity is quenched when the Au NP:Ru mole ratio is 14.8 x 10(-2). The rate of homogeneous charge transfer through thin layers of the nanocomposite deposited on glassy carbon electrodes increases with increasing nanoparticle loading. The homogeneous charge transport diffusion coefficient, D(CT), for the composite (AuNP:Ru mole ratio 13.2 x 10(-2)) is (2.8 +/- 0.8) x 10(-11) cm(2) s(-1) and is approximately 3-fold higher than that found for the pure metallopolymer. Significantly, despite the ability of the metal nanoparticles to quench the ruthenium-based emission, the electrochemiluminescence of the nanocomposite with a AuNP:Ru mole ratio of 4.95 x 10(-2) is approximately three times more intense than the parent metallopolymer. This enhancement arises from the increased rate of charge transport that leads to a greater number of excited states per unit time while minimizing the quenching effects. The implications of these findings for the design of electrochemiluminescent sensors are discussed.
Collapse
Affiliation(s)
- Anitha Devadoss
- Biomedical Diagnostics Institute, National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | | | | | | | | | | | | |
Collapse
|
9
|
Bertoncello P, Peruffo M, Li F, Unwin PR. Functional electrochemically-active ultra-thin Nafion films. Colloids Surf A Physicochem Eng Asp 2008. [DOI: 10.1016/j.colsurfa.2007.12.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
10
|
|
11
|
Marx VM, Girgis H, Heiney PA, Hegmann T. Bent-core liquid crystal (LC) decorated gold nanoclusters: synthesis, self-assembly, and effects in mixtures with bent-core LC hosts. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b802554a] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Bertoncello P, Dennany L, Forster RJ, Unwin PR. Nafion−Tris(2-2‘-bipyridyl)ruthenium(II) Ultrathin Langmuir−Schaefer Films: Redox Catalysis and Electrochemiluminescent Properties. Anal Chem 2007; 79:7549-53. [PMID: 17713967 DOI: 10.1021/ac070811m] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simple procedure to incorporate tris(2-2'-bipyridyl)ruthenium(II), [Ru(bpy)3]2+, into Nafion Langmuir-Schaefer (LS) films is described. Nafion LS films (tens of nanometers thick) were formed on quartz glass and indium tin oxide (ITO) directly from Nafion-[Ru(bpy)3]2+ Langmuir films assembled at the water-air interface. This procedure allowed the direct incorporation of [Ru(bpy)3]2+ into Nafion films without the need for subsequent loading. UV-vis spectroscopy confirmed the successful incorporation of [Ru(bpy)3]2+ within the LS films and showed that the amount of [Ru(bpy)3]2+ immobilized in this way scaled with film thickness. Voltammetric studies on ITO-modified electrodes confirmed the successful incorporation of [Ru(bpy)3]2+ and demonstrated that [Ru(bpy)3]2+ was retained within the ultrathin films over a long time scale. These electrodes were tested for the electrocatalytic reduction of tripropylamine. Significant catalysis was observed due to the rapid turnover of [Ru(bpy)3]2+/3+ between the electrode surface and outer boundary of the film, as a direct consequence of the ultrathin film dimensions. Concomitant electrochemiluminescence (ECL) was demonstrated highlighting the potential of this material for sensing applications.
Collapse
Affiliation(s)
- Paolo Bertoncello
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom.
| | | | | | | |
Collapse
|
13
|
Bertoncello P, Wilson NR, Unwin PR. One-step formation of ultra-thin chemically functionalized redox-active Langmuir-Schaefer Nafion films. SOFT MATTER 2007; 3:1300-1307. [PMID: 32900096 DOI: 10.1039/b709278d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A novel "one-step procedure" to incorporate different cationic redox-active species within ultra-thin Nafion films is reported. Ultra-thin films of Nafion containing trimethylammonioferrocene (FA), tris(2,2'-bipyridyl)ruthenium(), Ru(bpy), and hexaaminoruthenium(), [Ru(NH)], were prepared using the Langmuir-Schaefer (LS) technique. The morphology and thickness of the films were evaluated with atomic force microscopy (AFM). Film thicknesses were 1.9 ± 0.7, 1.8 ± 0.9, 1.5 ± 0.9 nm per layer for Nafion-FA, Nafion-Ru(bpy)and Nafion-[Ru(NH)], respectively. Electrochemical data confirmed the successful incorporation of the mediators into the films and proved that the redox activity was maintained during extensive voltammetric cycling. Key parameters such as surface coverage, concentration of the mediator within the films and apparent diffusion coefficients were extracted using cyclic voltammetry. To demonstrate the utility of the redox-active films for sensing applications, films with Ru(bpy) incorporated were utilized for the electrocatalysis of oxalate in aqueous solution.
Collapse
Affiliation(s)
- Paolo Bertoncello
- Department of Chemistry, University of Warwick, Coventry, UKCV4 7AL. (Prof. P. R. Unwin) (Dr P. Bertoncello)
| | - Neil R Wilson
- Department of Physics, University of Warwick, Coventry, UKCV4 7AL
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick, Coventry, UKCV4 7AL. (Prof. P. R. Unwin) (Dr P. Bertoncello)
| |
Collapse
|
14
|
Nanoparticles in Liquid Crystals: Synthesis, Self-Assembly, Defect Formation and Potential Applications. J Inorg Organomet Polym Mater 2007. [DOI: 10.1007/s10904-007-9140-5] [Citation(s) in RCA: 281] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
15
|
Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films. ACTA ACUST UNITED AC 2007. [DOI: 10.1007/s11426-007-2030-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Fabrication of new fullerene composite membranes and their application in proton exchange membrane fuel cells. J Memb Sci 2007. [DOI: 10.1016/j.memsci.2006.12.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
17
|
Milsom EV, Novak J, Green SJ, Zhang X, Stott SJ, Mortimer RJ, Edler K, Marken F. Layer-by-layer deposition of open-pore mesoporous TiO2-Nafion® film electrodes. J Solid State Electrochem 2007. [DOI: 10.1007/s10008-006-0247-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Bertoncello P, Peruffo M, Unwin PR. Formation and evaluation of electrochemically-active ultra-thin palladium–Nafion nanocomposite films. Chem Commun (Camb) 2007:1597-9. [PMID: 17530071 DOI: 10.1039/b702537h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple method for producing electrochemically-active palladium nanoparticles within ultra-thin Nafion films is described.
Collapse
Affiliation(s)
- Paolo Bertoncello
- Department of Chemistry, University of Warwick, Coventry, UKCV4 7AL.
| | | | | |
Collapse
|
19
|
Bertoncello P, Ciani I, Li F, Unwin PR. Measurement of apparent diffusion coefficients within ultrathin nafion Langmuir-Schaefer films: comparison of a novel scanning electrochemical microscopy approach with cyclic voltammetry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:10380-8. [PMID: 17129006 DOI: 10.1021/la061214i] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The use of scanning electrochemical microscopy (SECM) to evaluate the apparent diffusion coefficient, Dapp, of redox-active species in ultrathin Nafion films is described. In this technique, an ultramicroelectrode (UME) tip, positioned close to a film on a macroscopic electrode, is used to oxidize (or reduce) a species in bulk solution, causing the tip-generated oxidant (reductant) to diffuse to the film/solution interface. The oxidation (reduction) of film-confined species regenerates the reductant (oxidant) in solution, leading to feedback to the UME. A numerical model is developed that allows Dapp to be determined. For these studies, ultrathin films of Nafion were prepared using the Langmuir-Schaefer (LS) technique and loaded with an electroactive species, either the ferrocene derivative ferrocenyltrimethylammonium cation, FA+, or tris(2,2'-bipyridyl)ruthenium(II), Ru(bpy)32+. The morphology and the thickness of the Nafion LS films (1.5 +/- 0.2 nm per layer deposited) were evaluated using atomic force microscopy (AFM). For comparison with the SECM measurements, cyclic voltammetry (CV) was employed to evaluate the concentration of electroactive species within the Nafion LS films and to determine Dapp. The latter was found to be essentially invariant with film thickness, but the value for Ru(bpy)32+ was 1 order of magnitude larger than for FA+. CV and SECM measurements yield different values of Dapp, and the underlying reasons are discussed. In general, the Dapp values for these films are considerably smaller than for recast Nafion films, which can be attributed to the compactness of Nafion LS films. Nonetheless, the ultrathin nature of the films leads to fast response times, and we thus expect that these modified electrodes could find applications in sensing, electroanalysis, and electrocatalysis.
Collapse
Affiliation(s)
- Paolo Bertoncello
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, United Kingdom.
| | | | | | | |
Collapse
|