Imperial College London

DrSze YinTan

Faculty of EngineeringDepartment of Chemical Engineering

Research Associate
 
 
 
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Contact

 

s.tan

 
 
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Location

 

B432MACE ExtensionSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

17 results found

Tan S-Y, Hallett J, Geoff K, 2020, Electrodeposition of lead from methanesulfonic acid and methanesulfonate ionic liquid derivatives, Electrochimica Acta, Vol: 353, Pages: 1-11, ISSN: 0013-4686

The influence is reported of electrolyte composition on the electrochemistry of PbII and electrodeposition morphology of Pb in aqueous methanesulfonic acid (MSA) and two methanesulfonate-based ionic liquids: 1-butyl-3-methylimidazolium methanesulfonate and N,N-dimethylbutylammonium methanesulfonate. Cyclic voltammetry and chronoamperometry indicated that the reduction of PbII ions to Pb was a diffusion-controlled process proceeding via a two-electron transfer process at -0.67 V vs. Ag (1 M MSA) and involved 3-D progressive nucleation. Scanning electron microscopy showed a strong influence of deposition potential and electrolyte composition on the morphology of Pb deposits. Experimental data was used to model predictions of the specific electrical energy consumption for cathodic PbII electrodeposition coupled with either anodic oxygen evolution or PbO2 electrodeposition.

Journal article

Tan SY, Payne DJ, Hallett JP, Kelsall GHet al., 2019, Developments in electrochemical processes for recycling lead-acid batteries, Current Opinion in Electrochemistry, Vol: 16, Pages: 83-89, ISSN: 2451-9103

The lead-acid battery recycling industry is very well established, but the conventional pyrometallurgical processes are far from environmentally benign. Hence, recent developments of lead-acid battery recycling technologies have focused on low-temperature (electro-)hydrometallurgical processes, the subject of this review, covering modified electrolytes, improved reaction engineering, better reactor design and control of operating conditions.

Journal article

Li J, Bentley CL, Tan S-Y, Mosali VSS, Rahman MA, Cobb SJ, Guo S-X, Macpherson JV, Unwin PR, Bond AM, Zhang Jet al., 2019, Impact of sp(2) Carbon Edge Effects on the Electron-Transfer Kinetics of the Ferrocene/Ferricenium Process at a Boron-Doped Diamond Electrode in an Ionic Liquid, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 123, Pages: 17397-17406, ISSN: 1932-7447

Journal article

Tan S-Y, Perry D, Unwin PR, 2018, Double layer effects in voltammetric measurements with scanning electrochemical microscopy (SECM), JOURNAL OF ELECTROANALYTICAL CHEMISTRY, Vol: 819, Pages: 240-250, ISSN: 1572-6657

Journal article

Tan S-Y, Unwin PR, Macpherson JV, Zhang J, Bond AMet al., 2017, Probing Electrode Heterogeneity using Fourier-Transformed Alternating Current Voltammetry: Protocol Development, Electrochimica Acta, Vol: 240, Pages: 514-521, ISSN: 0013-4686

Journal article

Tan S-Y, Lazenby RA, Bano K, Zhang J, Bond AM, Macpherson JV, Unwin PRet al., 2017, Comparison of fast electron transfer kinetics at platinum, gold, glassy carbon and diamond electrodes using Fourier-transformed AC voltammetry and scanning electrochemical microscopy, Phys. Chem. Chem. Phys., Vol: 19, Pages: 8726-8734, ISSN: 1463-9076

Journal article

Tan S-Y, Unwin PR, Macpherson JV, Zhang J, Bond AMet al., 2017, Probing Electrode Heterogeneity Using Fourier-Transformed Alternating Current Voltammetry: Application to a Dual-Electrode Configuration, ANALYTICAL CHEMISTRY, Vol: 89, Pages: 2830-2837, ISSN: 0003-2700

Journal article

Zhang G, Tan S-Y, Patel AN, Unwin PRet al., 2016, Electrochemistry of Fe3+/2+ at highly oriented pyrolytic graphite (HOPG) electrodes: kinetics, identification of major electroactive sites and time effects on the response, Physical Chemistry Chemical Physics, Vol: 18, Pages: 32387-32395, ISSN: 1463-9076

The electrochemistry of the Fe3+/2+ redox couple has been studied on highly oriented pyrolytic graphite (HOPG) samples that differ in step edge density by 2 orders of magnitude, to elucidate the effect of surface structure on the electron transfer (ET) kinetics. Macroscopic cyclic voltammetry measurements in a droplet-cell arrangement, highlight that the Fe3+/2+ process is characterised by slow ET kinetics on HOPG and that step edge coverage has little effect on the electrochemistry of Fe3+/2+. A standard heterogeneous ET rate constant of ∼5 × 10−5 cm s−1 for freshly cleaved HOPG was derived from simulation of the experimental results, which fell into the range of the values reported for metal electrodes, e.g. platinum and gold, despite the remarkable difference in density of electronic states (DOS) between HOPG and metal electrodes. This provides further evidence that outer-sphere redox processes on metal and sp2 carbon electrodes appear to be adiabatic. Complementary surface electroactivity mapping of HOPG, using scanning electrochemical cell microscopy, reveal the basal plane to be the predominant site for the Fe3+/2+ redox process. It is found that time after cleavage of the HOPG surface has an impact on the surface wettability (and surface contamination), as determined by contact angle measurements, and that this leads to a slow deterioration of the kinetics. These studies further confirm the importance of understanding and evaluating surface structure and history effects in HOPG electrochemistry, and how high resolution measurements, coupled with macroscopic studies provide a holistic view of electrochemical processes.

Journal article

Güell AG, Tan S, Unwin PR, Zhang Get al., 2016, Electrochemistry at Highly Oriented Pyrolytic Graphite (HOPG): Toward a New Perspective, Electrochemistry of Carbon Electrodes, Editors: Alkire, Bartlett, Lipkowski, Publisher: John Wiley & Sons, ISBN: 9783527697519

This chapter is concerned with electrochemistry at, and of, highly oriented pyrolytic graphite (HOPG), a material that has been studied intermittently for several decades, but which is of enduring interest particularly as a comparison to other types of carbon electrodes. It presents an overview of the field, with a particular focus on recent work that allows key models of the HOPG electrochemistry to be assessed. Recent developments in scanning probe microscopy have provided new opportunities to determine the electrical and electrochemical characteristics of graphite with unprecedented detail and spatial resolution. These developments receive major attention in the chapter. An overview of the structure and electronic properties of graphite is provided. The chapter also assesses early electrochemical measurements at HOPG, which tended to rely on macroscopic measurements and correlations between different macroscopic quantities. It highlights that the new understanding of HOPG electrodes has implications for wider electrochemistry.

Book chapter

Tan S-Y, Zhang J, Bond AM, Macpherson JV, Unwin PRet al., 2016, Impact of Adsorption on Scanning Electrochemical Microscopy Voltammetry and Implications for Nanogap Measurements, Analytical Chemistry, Vol: 88, Pages: 3272-3280, ISSN: 0003-2700

Journal article

Troadec T, Tan S-Y, Wedge CJ, Rourke JP, Unwin PR, Chaplin ABet al., 2016, One-Electron Oxidation of [M(PtBu3)2] (M=Pd, Pt): Isolation of Monomeric [Pd(PtBu3)2]+ and Redox-Promoted C−H Bond Cyclometalation, Angewandte Chemie, Vol: 128, Pages: 3818-3821, ISSN: 0044-8249

Journal article

Troadec T, Tan S-Y, Wedge CJ, Rourke JP, Unwin PR, Chaplin ABet al., 2016, One-Electron Oxidation of [M((PBu3)-Bu-t)(2)] (M=Pd, Pt): Isolation of Monomeric [Pd((PBu3)-Bu-t)(2)](+) and Redox-Promoted C-H Bond Cyclometalation, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 55, Pages: 3754-3757, ISSN: 1433-7851

Journal article

Li L, Clarkson GJ, Lees MR, Howson SE, Tan S-Y, Turner SS, Scott Pet al., 2015, Iron and Manganese Complexes of 2-Carbonyl Pyrrolyls: Scorpionate Sandwich Anions and Extended Structures, Organometallics, Vol: 34, Pages: 2543-2549, ISSN: 0276-7333

Journal article

Gueell AG, Cuharuc AS, Kim Y-R, Zhang G, Tan S-Y, Ebejer N, Unwin PRet al., 2015, Redox-Dependent Spatially Resolved Electrochemistry at Graphene and Graphite Step Edges, ACS NANO, Vol: 9, Pages: 3558-3571, ISSN: 1936-0851

Journal article

Patel AN, Tan S-Y, Miller TS, Macpherson JV, Unwin PRet al., 2013, Comparison and Reappraisal of Carbon Electrodes for the Voltammetric Detection of Dopamine, ANALYTICAL CHEMISTRY, Vol: 85, Pages: 11755-11764, ISSN: 0003-2700

Journal article

Patel AN, Tan S-Y, Unwin PR, 2013, Epinephrine electro-oxidation highlights fast electrochemistry at the graphite basal surface, CHEMICAL COMMUNICATIONS, Vol: 49, Pages: 8776-8778, ISSN: 1359-7345

Journal article

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