Robert C. T. Slade

University of Surrey, Guilford, England, United Kingdom

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Publications (162)645.06 Total impact

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    ABSTRACT: Nitrogen-doped crumpled graphene (NCG) is successfully synthesized via vapor phase deposition of polypyrrole onto graphene aerogel followed by thermal treatment. The NCG was explored as an electrocatalyst for the oxygen reduction reaction, showing comparable electrocatalytic performance with the commercial Pt/C in alkaline membrane exchange fuel cells because of the well-regulated nitrogen doping and the robust micro-3D crumpled porous nanostructure.Keywords: nitrogen-doped graphene; vapor phase polymerization; oxygen reduction reaction; alkaline membrane fuel cell
    ACS Applied Materials & Interfaces 03/2015; 7(13). DOI:10.1021/acsami.5b01025 · 6.72 Impact Factor
  • Sarah L. Mallinson · John R. Varcoe · Robert C. T. Slade ·
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    ABSTRACT: The applicability of amine-functionalised anion-exchange membranes (AEMs) for use in the all-vanadium redox flow battery has been studied. A selection of radiation-grafted aminated membranes functionalised with dimethylamine, trimethylamine or diazabicyclo(2,2,2)octane were extensively tested. The success of each grafting process was confirmed by Raman and infrared spectroscopies, titrimetry and ionic conductivity measurements. The amine-functionalised membranes were found to have poor thermo-oxidative stability and high vanadium cation permeabilities. The results highlight the importance of balancing ionic conductivity with vanadium cation permeability and indicate that amine-based functional groups may not be suitably stable for the membranes to remain true AEMs when in use in the all-vanadium redox flow battery.
    Electrochimica Acta 09/2014; 140:145-151. DOI:10.1016/j.electacta.2014.06.058 · 4.50 Impact Factor
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    Arvinder Singh · Alexander J Roberts · Robert C T Slade · Amreesh Chandra ·
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    ABSTRACT: The electrochemical performance of asymmetric supercapacitors (ASCs) using MWCNTs/NiS and graphene nanoplatelets as positive and negative electrode, respectively, are reported. Nickel sulfide nanoparticles can be decorated on multiwall carbon nanotubes using a hydrothermal synthesis process, with graphene nanoplatelets obtained via a chemical route. The fabricated ACSs were operated over a potential window of 1.4 V with a specific capacitance of 181 F g -1 observed at 1 A g -1 . The ASCs were cycled at 2 A g -1 showing 92% retention of initial capacitance after 1000 cycles. .
    Journal of Materials Chemistry A 08/2014; DOI:10.1039/C4TA02870H · 7.44 Impact Factor
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    225th Annual Electrochemical Society Meeting - Orlando; 05/2014
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    ABSTRACT: Nanostructured thin films of vanadium oxides were deposited using electric field assisted chemical vapour deposition. The films were characterised using scanning electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. It was found that the films had open and porous morphologies with extremely small (5 nm) surface features. The films were made into supercapacitor cells and tested using cyclic voltammetry. It was found that stable asymptotic values specific capacitance values as high as 3700 [small mu ]F cm-2 could be obtained with good cycling behaviour. Electrodes synthesized in this way show promise for applications in fields such as supercapacitors.
    Journal of Materials Chemistry 05/2014; 2(17). DOI:10.1039/c3ta14185c · 7.44 Impact Factor
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    ABSTRACT: The relationship between the diversity of mixed-species microbial consortia and their electrogenic potential in the anodes of microbial fuel cells was examined using different diversity measures as predictors. Identical microbial fuel cells were sampled at multiple time-points. Biofilm and suspension communities were analysed by denaturing gradient gel electrophoresis to calculate the number and relative abundance of species. Shannon and Simpson indices and richness were examined for association with power using bivariate and multiple linear regression, with biofilm DNA as an additional variable. In simple bivariate regressions, the correlation of Shannon diversity of the biofilm and power is stronger (r = 0.65, p = 0.001) than between power and richness (r = 0.39, p = 0.076), or between power and the Simpson index (r = 0.5, p = 0.018). Using Shannon diversity and biofilm DNA as predictors of power, a regression model can be constructed (r = 0.73, p < 0.001). Ecological parameters such as the Shannon index are predictive of the electrogenic potential of microbial communities.
    Bioresource Technology 03/2014; 156:84–91. DOI:10.1016/j.biortech.2014.01.041 · 4.49 Impact Factor
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    ABSTRACT: A novel alkaline exchange ionomer (AEI) was prepared from the radiation-grafting of vinylbenzyl chloride (VBC) onto poly(ethylene-co-tetrafluoroethylene) [ETFE] powders with powder particle sizes of less than 100 mm diameter. Quaternisation of the VBC grafted ETFE powders with trimethylamine resulted in AEIs that were chemically the same as the ETFE-based radiation-grafted alkaline anion exchange membranes (AAEM) that had been previously developed for use in low temperature alkaline polymer electrolyte fuel cells (APEFC). The integration of the AEI powders into the catalyst layers (CL) of both electrodes resulted in a H2/O2 fuel cell peak power density of 240 mW cm�2 at 50 C (compared to 180 mW cm�2 with a benchmark membrane electrode assembly containing identical components apart from the use of a previous generation AEI). This result is promising considering the wholly un-optimised nature of the AEI inclusion into the catalyst layers.
    Journal of Materials Chemistry A 02/2014; 2(14):5124 - 5130. DOI:10.1039/c4ta00558a · 7.44 Impact Factor
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    ABSTRACT: Mediator-less, direct electro-catalytic reduction of oxygen to water by bilirubin oxidase (Myrothecium sp.) was obtained on anthracene-modified, multi-walled carbon nanotubes. H2O2 was found to significantly and irreversibly affect the electro-catalytic activity of bilirubin oxidase, whereas similar electrodes comprised of laccase (Trametes versicolor) were reversibly inhibited.
    Chemical Communications 01/2014; 50:94-96. DOI:10.1039/c3cc47689h · 6.83 Impact Factor
  • Alexander J. Roberts · Robert C. T. Slade ·
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    ABSTRACT: Birnessite MnO2 nanotubes of high specific surface area have been used as one electrode material in supercapacitors with a commercial-carbon-based second electrode ((NH4)2SO4(aq.) electrolyte). Assembled cells have been subjected to full electrochemical testing at temperatures [less-than-or-equal]80 [degree]C. At elevated temperatures, specific capacitance as high as 700 F g-1 has been observed. The increase in specific capacitance with temperature has been found to be at a cost to cycling performance. Furthermore, the time spent at elevated temperatures "at rest" has been shown to have a major effect on device lifetime. It has been found that at 80 [degree]C, without cycling, such devices lose all significant capacitance after 21 days. The findings herein are believed to have major implications for transport, storage lifetime and ultimate utilization of such systems.
    Journal of Materials Chemistry 12/2013; 1(45-45):14140-14146. DOI:10.1039/c3ta13213g · 7.44 Impact Factor
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    ABSTRACT: Palladium-Nickel (Pd-Ni) hollow nanoparticles were synthesized via a modified galvanic replacement method using Ni nanoparticles as sacrificial templates in an aqueous medium. X-ray diffraction and transmission electron microscopy show that the as-synthesized nanoparticles are alloyed nanostructures and have hollow interiors with an average particle size of 30 nm and shell thickness of 5 nm. Compared with the commercially available Pt/C or Pd/C catalysts, the synthesized PdNi/C has superior electrocatalytic performance towards the oxygen reduction reaction, which makes it a promising electrocatalyst for alkaline anion exchange membrane fuel cells and alkali-based air-batteries. The electrocatalyst is finally examined in an H2/O2 alkaline anion exchange membrane fuel cell; the results show that such electrocatalysts could work in a real fuel cell application as a more efficient catalyst than state-of-the-art commercially available Pt/C.
    ACS Applied Materials & Interfaces 11/2013; 5(23). DOI:10.1021/am404090n · 6.72 Impact Factor
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    ABSTRACT: Hydrogen peroxide production by glucose oxidase (GOx) and its negative effect on laccase performance have been studied. Simultaneously, FAD-dependent glucose dehydrogenase (FAD-GDH), an O2-insensitive enzyme, has been evaluated as a substitute. Experiments focused on determining the effect of the side reaction of GOx between its natural electron acceptor O2 (consumed) and hydrogen peroxide (produced) in the electrolyte. Firstly, oxygen consumption was investigated by both GOx and FAD-GDH in the presence of substrate. Relatively high electrocatalytic currents were obtained with both enzymes. O2 consumption was observed with immobilized GOx only, whilst O2 concentration remained stable for the FAD-GDH. Dissolved oxygen depletion effects on laccase electrode performances were investigated with both an oxidizing and a reducing electrode immersed in a single compartment. In the presence of glucose, dramatic decreases in cathodic currents were recorded when laccase electrodes were combined with a GOx-based electrode only. Furthermore, it appeared that the major loss of performance of the cathode was due to the increase of H2O2 concentration in the bulk solution induced laccase inhibition. 24 h stability experiments suggest that the use of O2-insensitive FAD-GDH as to obviate in situ peroxide production by GOx is effective. Open-circuit potentials of 0.66 ± 0.03 V and power densities of 122.2 ± 5.8 μW cm(-2) were observed for FAD-GDH/laccase biofuel cells.
    Physical Chemistry Chemical Physics 10/2013; 15:19371-19379. DOI:10.1039/c3cp53351d · 4.49 Impact Factor

  • 64th Annual International Society Meeting - Queretaro, Mexico; 09/2013
  • Alexander J Roberts · Angela F. Danil de Namor · Robert C T Slade ·
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    ABSTRACT: Birnessite nanotubes and activated carbon electrodes have been used in supercapacitor cells to assess the performance of new aqueous based electrolyte systems at temperatures as low as -30 °C. The addition of ethylene glycol to aqueous sodium, lithium, potassium and ammonium sulfates has resulted in electrolytes that are still in liquid phase at such low temperatures. Extensive electrochemical testing showed that in such systems, operation of these aqueous based supercapacitors is possible at -30 °C with a specific capacitance of over 30 F g(-1) and good cycleability.
    Physical Chemistry Chemical Physics 02/2013; 15(10). DOI:10.1039/c3cp50359c · 4.49 Impact Factor
  • Robert C. T. Slade · Jamie P. Kizewski · Simon D. Poynton · Rong Zeng · John R. Varcoe ·
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    ABSTRACT: The disruptive approach of applying alkaline anion-exchange membranes (AEMs) in alkaline membrane fuel cells (AMFCs) potentially meets several of the challenges facing other approaches to low temperature fuel cells, including the otherwise high catalyst and fuel costs. Thus, the move to alkaline conditions at the electrodes opens the potential use of a range of low cost non-precious-metal catalysts, as opposed to the otherwise necessary use of platinum-group-metal (PGM) based catalysts. Further, it becomes possible to consider hydrogen fuels containing substantial amounts of impurities, whereas an acidic membrane approach (that in proton exchange membrane fuel cells, PEMFCs) requires high-purity gases and PGM catalysts.
    Fuel Cells, 01/2013: pages 9-29; , ISBN: 978-1-4614-5784-8
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    Ross D Milton · Jessica Baur · John R Varcoe · Alfred E Thumser · Robert C T Slade ·
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    ABSTRACT: A glucose oxidase (GOd) bioelectrode exhibiting high performance, direct electron transfer (DET) has been prepared. Unprecedented redox peak current densities of 1 mA cm(-2) were observed alongside a clear electrochemical response to glucose. This system shows potential as a low cost, high performance enzymatic bioelectrode.
    Physical Chemistry Chemical Physics 06/2012; 14(27):9582-5. DOI:10.1039/c2cp41651d · 4.49 Impact Factor
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    ABSTRACT: The performance and dynamics of the bacterial communities in the biofilm and suspended culture in the anode chamber of sucrose-fed microbial fuel cells (MFCs) were studied by using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes followed by species identification by sequencing. The power density of MFCs was correlated to the relative proportions of species obtained from DGGE analysis in order to detect bacterial species or taxonomic classes with important functional role in electricity production. Although replicate MFCs showed similarity in performance, cluster analysis of DGGE profiles revealed differences in the evolution of bacterial communities between replicate MFCs. No correlation was found between the proportion trends of specific species and the enhancement of power output. However, in all MFCs, putative exoelectrogenic denitrifiers and sulphate-reducers accounted for approximately 24% of the bacterial biofilm community at the end of the study. Pareto-Lorenz evenness distribution curves extracted from the DGGE patterns obtained from time course samples indicated community structures where shifts between functionally similar species occur, as observed within the predominant fermentative bacteria. These results suggest the presence of functional redundancy within the anodic communities, a probable indication that stable MFC performance can be maintained in changing environmental conditions. The capability of bacteria to adapt to electricity generation might be present among a wide range of bacteria.
    Applied Microbiology and Biotechnology 01/2012; 93(1):423-37. DOI:10.1007/s00253-011-3590-y · 3.34 Impact Factor
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    ABSTRACT: A simple aqueous-processable alkaline ionomer (amenable to scale-up) has been developed for enhancing electrode/electrolyte interfaces in clean energy devices (e.g. alkaline polymer electrolyte membranefuelcells). The water uptake of the alkaline ionomer is tuneable allowing its use as a tool for fundamental studies into these interfaces.
    Energy & Environmental Science 12/2011; 4(12-12):4925-4928. DOI:10.1039/c1ee02349g · 20.52 Impact Factor
  • C. A. Hancock · R.C.T. Slade · J.R. Varcoe · P.R. Slater ·
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    ABSTRACT: In this paper we report the successful incorporation of sulfate and phosphate into SrCoO3 leading to a change from a 2H- to a 3C-perovskite polymorph. Structural characterization by neutron diffraction showed extra weak peaks related to oxygen vacancy ordering, and these could be indexed on an expanded tetragonal cell, containing two inequivalent Co sites, similar to previously reported for Sb doped SrCoO3. Conductivity measurements on the doped systems showed a large enhancement compared to the undoped hexagonal system, consistent with corner-sharing of CoO6 octahedra for the former. Further work on the doped samples shows, however, that they are metastable, transforming back to the hexagonal cell on annealing at intermediate temperatures. The incorporation of Fe was shown, however, to improve the stability at intermediate temperatures, and these co-doped phases also showed high conductivities.
    Journal of Solid State Chemistry 11/2011; 184(11):2972-2977. DOI:10.1016/j.jssc.2011.08.040 · 2.13 Impact Factor
  • Alexander J. Roberts · Robert C. T. Slade ·
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    ABSTRACT: Birnessite nanotubes have been made through a templated hydrothermal route. Variations in experimental conditions have resulted in differing morphologies of high specific surface area. After forming into electrodes in supercapacitor test cells, good cycleability was observed with specific capacitances approaching 350 F g−1 at low discharge current densities.
    Energy & Environmental Science 08/2011; 4(8-8):2813-2817. DOI:10.1039/c1ee01394g · 20.52 Impact Factor
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    ABSTRACT: The spatiotemporal development of a bacterial community in an exoelectrogenic biofilm was investigated in sucrose-fed longitudinal tubular microbial fuel cell reactors, consisting of two serially connected modules. The proportional changes in the microbial community composition were assessed by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) and DNA sequencing in order to relate them to the performance and stability of the bioelectrochemical system. The reproducibility of duplicated reactors, evaluated by cluster analysis and Jaccard's coefficient, shows 80-90% similarity in species composition. Biofilm development through fed-batch start-up and subsequent stable continuous operation results in a population shift from γ-Proteobacteria- and Bacteroidetes- to Firmicutes-dominated communities, with other diverse species present at much lower relative proportions. DGGE patterns were analysed by range-weighted richness (Rr) and Pareto-Lorenz evenness distribution curves to investigate the evolution of the bacterial community. The first modules shifted from dominance by species closely related to Bacteroides graminisolvens, Raoultella ornithinolytica and Klebsiella sp. BM21 at the start of continuous-mode operation to a community dominated by Paludibacter propionicigenes-, Lactococcus sp.-, Pantoea agglomerans- and Klebsiella oxytoca-related species with stable power generation (6.0 W/m(3)) at day 97. Operational strategies that consider the dynamics of the population will provide useful parameters for evaluating system performance in the practical application of microbial fuel cells.
    Applied Microbiology and Biotechnology 03/2011; 90(3):1179-91. DOI:10.1007/s00253-011-3181-y · 3.34 Impact Factor

Publication Stats

5k Citations
645.06 Total Impact Points


  • 1999-2015
    • University of Surrey
      • • Department of Chemistry
      • • Faculty of Health and Medical Sciences
      Guilford, England, United Kingdom
  • 1982-2001
    • University of Exeter
      Exeter, England, United Kingdom
  • 2000
    • Milton Keynes College
      Milton Keynes, England, United Kingdom
  • 1996
    • Slovak Academy of Sciences
      • Institute of Inorganic Chemistry
      Presburg, Bratislavský, Slovakia
  • 1994
    • Università degli Studi di Perugia
      • Department of Chemistry
      Perugia, Umbria, Italy
  • 1988
    • University of Kent
      Cantorbery, England, United Kingdom
  • 1980
    • The University of York
      • Department of Chemistry
      York, England, United Kingdom