Photo-stability of the Titan Yellow dye sensitized and Ethylenediaminetetraacetate photoreduced photogalvanic system

Abstract

Photogalvanic cells are solar power and storage devices. Extensive study on the photo-stability and durability aspect of these cells has not attracted the attention of the researchers. With this aim, the present work reports the electrical output and stability study of the Titan Yellow sensitized photo-galvanic cells. The observed electrical output is 823 mV potential, 2800 μA current, and 511.10 μW power. The observed potential decay rate over 52.18 h is very low (i.e., 1.59 mV/h only) during illumination. This observation shows quite good photo-stability of the cell with respect to the open-circuit potential. The observed current decay rate over 52.18 h is very high (i.e., 15.67 μA/h) during illumination. This observation shows less photo-stability of the cell with respect to the short-circuit current. From initial charging to 1st re-charging to 2nd re-charging of the same cell, the power output decreases under experimental conditions. Overall, the power decay is observed with time in both dark and illuminated conditions. The trend of fall of power is suggestive of the inverse relation between half change time and initial power, and the power decay is of non-zero and non-first order decay. The dye decay and temperature rise in the electrolyte is observed. The power decay may be attributed to the photo-induced degradation of the dye electro-active species and high temperature induced aggregation (precipitation) of the Titan Yellow dye molecules. Despite this power decay, the Titan Yellow dye based photogalvanic cells are capable of producing solar power for sufficiently long hours.