Graphite counter electrode modified Tropaeolin-O photo-sensitized photogalvanic cells for solar power and storage

An optimization, photo-stability, and hysteresis property of the Graphite counter electrode-modified Tropaeolin-O (TPO) photo-sensitized photogalvanic (PG) cells has been investigated. A complex H-shaped cell design, a costly and delicate saturated calomel electrode (counter electrode), and a heavy sensitizer molecule (dye having high molecular weight, low diffusivity, and low photo-stability) have been exploited for fabricating most of the PG cells so far. All these factors are not suitable for the fabrication of durable and cheap PG cells. Therefore, in the present study, the highly conductive/catalytically active robust graphite electrode with TPO dye photosensitizer (having a low molecular weight, higher diffusivity, and higher photo-stability) has been exploited with diffusion-friendly low cost and a simple transparent cylindrical glass tube. The cheap and robust graphite counter electrode has been exploited for optimization and long-term study of the TPO photo-sensitized PG cells. The observed electrical output is potential 676 mV, current 2000 µA, and power 340.0 μW. The power, current, and efficiency, have been found quite independent of the illumination window size. The potential and current have been observed to be quite stable over a long time during illumination, and the same has been supported by the hysteresis study.