Improved Tri-iodide Reduction Reaction of Co-TMPP/C as a Non-Pt Counter Electrode in Dye-Sensitized Solar Cells

Abstract

:We report Co-tetramethoxyphenylporphyrin on carbon particles (Co-TMPP/C) as a non-Pt catalyst for tri-iodide reduction in dye-sensitized solar cells (DSSCs). The presence of well-dispersed carbon and cobalt source in the catalyst surface is confirmed by transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray analysis. In the C 1s, Co 2p, and N 1s peaks measured by X-ray photoelectron spectroscopy, the C-N, Co-N 4 , and N-C are assigned to the component at 285.7, 781.8, and 401 eV, respectively. Especially, the Co-TMPP/C shows improved current density, diffusion coefficient, and charge-transfer resistance in the I 3 − /I− redox reaction compared to conventional catalysts. Furthermore, in the DSSCs performance, the Co-TMPP/C shows increased short circuit current density, higher open circuit voltage, and improved cell efficieny in comparison with Pt/C.

CoOx@Co‐NC Catalyst with Dual Active Centers for Enhanced Oxygen Evolution: Breaking Trade‐Off of Particle Size and Metal Loading

“…[35] For 7.5 % CoO x @Co-NC shown in Figure 4d, two fitted peaks for Co 2p 3/2 were Co 3 + (780.6 eV) and Co-N 4 (781.8 eV), respectively. [4,23,36,37] The deconvoluted peaks in O 1s spectrum of 7.5 % CoO x @Co-NC located at 530.8 eV, 531.6 eV and 532.9 eV were associated to O bound to Co (Co-O), hydroxyl species or surface adsorbed O molecules (O OH À /O2 ) and adsorbed molecular water (O H2O ), respectively. [38] The appearance of Co-N 4 , Co 3 + and Co-O species in the XPS spectrums of 7.5 % CoO x @Co-NC indicated that the Co-N 4 macrocycles and CoO x nanoclusters were successfully formed after the direct thermal treatment of Co-OCN.…”