Polypyrrole/Ionic Liquid/Au Nanoparticle Counter-Electrodes for Dye-Sensitized Solar Cells: Improving Charge-Transfer Resistance at the CE/Electrolyte Interface

Abstract

To provide a viable alternative for counter electrodes used in dye sensitized solar cells, polypyrrole (PPy) based films have been synthesized via electrochemical deposition in the presence of the ionic liquid 1-butyl-3-methylimidazolium bis-(trifluoromethanesulfonyl) imidate (NTf 2 ) and incorporated with gold nanoparticles (Au nanop ). The films were analyzed by SEM, UV-Vis-NIR, Raman, Electrochemical impedance spectroscopy, Cyclic voltammetry and Conductivity measurements. The presence of the ionic liquid is found to result in a more conductive film, to improve catalytic reduction of I 3 − and the electrochemical reversibility of the electrode. In addition to increase conductivity, impedance spectroscopy has shown that incorporating Au nanop in the PPy/NTf 2 film helps improving the interfacial charge transportation, the electrocatalytic properties and solar energy conversion efficiency. DSSCs assembled with PPy based CE presented nearly the same J-V characteristic parameters as observed from conventional Pt based device.

Conductive N, S doped Copolymers as Stable Metal-Free Electrocatalysts for Water Splitting

“…Raman measurements provided more detailed structural information about the Ppy, Ptp, and Ppy–Ptp electrocatalysts (Figure b). In particular, the peaks at 1598 cm –1 for each sample confirm the presence of aromatic CC. − Furthermore, the peak observed at 1400 cm –1 is narrower and more intense in the Ppy–Ptp copolymer than those of Ppy and Ptp, thereby revealing an increase in the conjugated bond length in the copolymer electrocatalyst. Moreover, the peak at 702 cm –1 , which is only observed in the Ptp and Ppy–Ptp electrocatalysts, can be attributed to the C–S–C in-plane distortion. , The doublet peaks at 1080 and 1400 cm –1 indicate oxidized Ppy, while those at 1320 and 1400 cm –1 can be attributed to the Ppy ring stretching mode.…”

Rapid Analytical Instrumentation for Electrochemical Impedance Spectroscopy Measurements

“…Previous studies have typically measured EIS over millihertz to kilohertz frequency ranges. 27,28 Like supercapacitors, the impedance of solar cells changes significantly over different frequencies. In addition, the current levels in EIS measurements are relatively low.…”

Algorithm for Assessing the Convergence of a Cyclic Voltammetry to Its Limit Cycle

“…Nowadays, this electrochemical technique has become an important and widely used electroanalytical technique in many chemistry-related areas. It has been used to study the kinetics of redox processes [20], to study the stability of the reaction products [24], to determine the electron transfer kinetics [25] and to study the reversibility of redox reactions [26]. Furthermore, cyclic voltammetry has also been used to determine the formal reduction potential of an analyte [3], the ionic transport properties [19] and the diffusion coefficient of a given electroactive species [27].…”

“…However, in the decades of the 60s and the 70s, significant advances were made in the theory and the instrumentation of voltammetric methods, such as the development of low-cost operational amplifiers that enabled affordable potentiostats. 2 These advances boosted the practical applicability of voltammetric methods, leading to the actual situation where voltammetric methods are widely used in a large variety of fields, such as electrodeposition, 3 batteries, [4][5][6][7] fuel cells, 8,9 supercapacitors, 10,11 electrochemical advanced oxidation, [12][13][14] electrochemical sensors, [15][16][17][18] ionic liquids [19][20][21][22] and surfactants, 23 amongst many others.…”