TY - JOUR
T1 - The Effect of Solvent on the Seebeck Coefficient and Thermocell Performance of Cobalt Bipyridyl and Iron Ferri/Ferrocyanide Redox Couples
AU - Taheri, Abuzar
AU - MacFarlane, Douglas R.
AU - Pozo-Gonzalo, Cristina
AU - Pringle, Jennifer M.
PY - 2019/8/2
Y1 - 2019/8/2
N2 - The conversion of thermal energy to electricity using thermoelectrochemical cells (thermocells) is a developing approach to harvesting waste heat. The performance of a thermocell is highly dependent on the solvent used in the electrolyte, but the interplay of the various solvent effects is not yet well understood. Here, using the redox couples [Co(bpy)3][BF4]2/3 (bpy = 2,2′-bipyridyl) and (Et4N)3/(NH4)4Fe(CN)6, which have been designed to allow dissolution in different solvent systems (aqueous, non-aqueous, and mixed solvent), the effect of solvent on the Seebeck coefficient (Se) and cell performance was studied. The highest Se for a cobalt-based redox couple measured thus far is reported. Different trends in the Seebeck coefficients of the two redox couples as a function of the ratio of organic solvent to water were observed. The cobalt redox couple produced a more positive Se in organic solvent than in water, whereas addition of water to organic solvent resulted in a more negative Se for Fe(CN)6 3-/4-. UV-vis and IR investigations of the redox couples indicate that Se is affected by changes in solvent-ligand interactions in the different solvent systems.
AB - The conversion of thermal energy to electricity using thermoelectrochemical cells (thermocells) is a developing approach to harvesting waste heat. The performance of a thermocell is highly dependent on the solvent used in the electrolyte, but the interplay of the various solvent effects is not yet well understood. Here, using the redox couples [Co(bpy)3][BF4]2/3 (bpy = 2,2′-bipyridyl) and (Et4N)3/(NH4)4Fe(CN)6, which have been designed to allow dissolution in different solvent systems (aqueous, non-aqueous, and mixed solvent), the effect of solvent on the Seebeck coefficient (Se) and cell performance was studied. The highest Se for a cobalt-based redox couple measured thus far is reported. Different trends in the Seebeck coefficients of the two redox couples as a function of the ratio of organic solvent to water were observed. The cobalt redox couple produced a more positive Se in organic solvent than in water, whereas addition of water to organic solvent resulted in a more negative Se for Fe(CN)6 3-/4-. UV-vis and IR investigations of the redox couples indicate that Se is affected by changes in solvent-ligand interactions in the different solvent systems.
UR - http://www.scopus.com/inward/record.url?scp=85072717966&partnerID=8YFLogxK
U2 - 10.1071/CH19245
DO - 10.1071/CH19245
M3 - Article
AN - SCOPUS:85072717966
SN - 0004-9425
VL - 72
SP - 709
EP - 716
JO - Australian Journal of Chemistry
JF - Australian Journal of Chemistry
IS - 9
ER -