Modified and simplified photogalvanic cells: Solar energy harvesting using bromo cresol green dye with different electrodes and cell dimensions

Abstract

Fig. i-V characteristics (‘i’ vs ‘V’ curve) of the cells (cell no. 4–6) based on the electrolyte filled in non-coated simple glass tube during illumination for (a) Pt-Combination electrode pair (cell no. 4), (b) Pt-Cylindrical graphite electrode pair (cell no.5), and (c) Pt-Rectangular graphite electrode pair (cell no. 6); Power at power point (current vs power curve) of the cells based on the electrolyte filled in non-coated simple glass tube during illumination for (a′) Pt-Combination electrode pair based cell no.4 (power 804 µW at 2000 µA & 402 mV), (b’) Pt-Cylindrical graphite electrode pair based cell no.5 (power 1170 µW at 6000 µA & 195 mV), and (c′) Pt- Rectangular graphite electrode pair based cell no.6 (power 1080 µW at 4000 µA & 270 mV). • Various alternative electrode couples like, Pt and Combination electrode, Pt and cylindrical graphite electrode, and Pt and rectangular graphite electrode couples placed in the modified cell vessels have been exploited in present work. • Authors have used cell design as the simple glass tube instead of the conventional and complex H-shaped glass tube for cell fabrication. • The study has been done for H-shaped glass tubes, simple glass boiling tube, and simple glass beakers. • Authors have observed encouraging electrical output (power 1170 µW, current 8000 µA, and efficiency 9.02%) by simply simplifying the fabrication of the PG cell based on rectangular graphite electrode placed in simple non-blackened glass boiling tube. Photogalvanic cells fabricated of H-shaped glass tube having Platinum (Pt) and saturated calomel electrodes dipped in the electrolyte solution (photosensitizer-reductant-surfactant-alkali) are widely reported. The modification of the electrodes, shapes, and sizes of cells has evaded the attention of researchers in the field for further improvement in the cell performances. Therefore, the present study on the use of various alternative electrodes (combination electrode, cylindrical graphite, rectangular graphite) and alternative cell vessels (H-shaped tube, simple glass tube) has been done with aim of further increasing the electrical output of the photogalvanic cells. Various alternative electrode couples like Pt and Combination electrode, Pt and cylindrical graphite electrode, and Pt and rectangular graphite electrode couples placed in the modified cell vessels have been exploited in present work. The Bromo cresol green dye sensitizer-formaldehyde reductant photogalvanic cells using modified electrode couples dipped in the different types of the glass tube vessels (i.e., blackened H-shaped glass tube, non-blackened simple glass boiling tube) have been studied at an artificial sunlight illumination. For photogalvanic cell fabricated of the rectangular graphite electrode (0.6 cm × 2.3 cm) placed in a simple non-blackened glass boiling tube; the optimum cell performance in terms of the maximum power, short-circuit current, open-circuit potential, efficiency, and storage capacity is of the order of 1170 µW, 8000 µA, 1130 mV, 9.02 %, and 70 min, respectively. It is concluded that the use of readily available cheap graphite and cheap boiling tubes provides an opportunity for simplified fabrication of the photogalvanic cells at reduced cost with the advantage of greatly enhanced electrical output for future studies.