Carbon electrode material assisted Tropaeline-O dye sensitized solar power and storage through the cylindrical photo-galvanic cell design

Solar energy can be harvested and stored by developing photo-galvanic cells. But, these solar cells are characterized by drawbacks like exploitation of costly and delicate saturated calomel electrode, complex H-shaped cell design, and less photo-stable heavy dye sensitizer molecules with low diffusivity. These factors are unfavorable for designing cheap and durable cells. Therefore, the role of cheap and robust carbon electrode material (graphite counter electrode) in simple cell design and quite photo-stable low molecular weight dye is of utmost importance. Further, the role of optimization and most suitable illumination window size of cell in enhancing cells’ efficiency can also be not denied. Therefore, in present research, the low molecular weight Tropaeline-O dye photo-sensitizer with higher diffusion with highly catalytically active/conductive/robust carbon electrode material have been explored in a loosely sealed cylindrical shaped transparent glass cell design. The workability of the photo-galvanic cells has been studied in present research at low intensity, i.e., 3.24 mWcm -2 . After optimization at this low intensity, the observed power, current, potential, and efficiency is 266.0 μW, 2000 μA, 753 mV, and 5.79 %, respectively. For this photo-galvanic chemical system, the optimum value of the cell’s electrical parameters is as: dark potential 479 mV, maximum potential 768 mV, open-circuit potential 753 mV, maximum current 12000 μA, short-circuit current 2000 μA, current at power point 1900 μA, potential at power point 140 mV, power at power point 266.0 μW, fill factor 0.17, and conversion efficiency 5.79 %. The optimal cell performance has been obtained at following optimum cell fabrication parameters: 0.03 × 10 -5 M Tropaeline-O, pH 13.72, 0.99 × 10 -3 M Oxalic acid, 3.0 × 10 -2 M Benzalkonium chloride, Rectangular Pt electrode’s dimensions’ 05 mm × 05 mm, Rectangular shaped graphite counter electrode (length 20 mm, width 04 mm), a glass tube (length 40 mm, diameter 28 mm, cylindrical-shaped, transparent, rubber corked, total 6.0 ml solution used), illuminating intensity 3.24 mWcm -2 , diffusion length 05 mm, 22.20 o C room temperature, and pre-illuminated electrolyte solution temperature 20.10 o C. Further, the illumination window size of the cell is found to be insignificant to the magnitude of generated power. The Tropaeline-O dye/ waste carbon electrode material in a cylindrical cell design have been found to obey same principles as reported for other photogalvanics. The observed power storage capacity of the cell is 120 minutes in present research, and it is relatively better than storage capacity of the some reported photo-galvanic cells. • Photogalvanic cell (PG cell) provides for solar power with simultaneous storage capacity as well. • The PG cells have used so far unfavorable cell design like the complex H-shaped design, heavy sensitizer molecules with low diffusivity and low photo-stability. • A simple cell cylindrical corked cell design having the Tropaeline-O dye photosensitizer, oxalic acid reductant, Benzalkonium chloride surfactant, very small Pt electrode as working electrode, and Graphite counter electrode has been studied in the present work. • The power, current and efficiency have been obtained quite similar at all illumination window sizes studied in the present work. • The potential and current has been observed to be quite stable over long time during illumination, and the same has been supported by the hysteresis study. • For this photogalvanic chemical system, the optimum value of the cell’s electrical parameters is as the potential 753 mV, current 2000 μA, and power 266.0 μW.