Use of Congo red dye-formaldehyde as a new sensitizer-reductant couple for enhanced simultaneous solar energy conversion and storage by photogalvanic cells at the low and artificial sun intensity

The photogalvanic cells (PG) are the promising and renewable electrochemical energy devices capable of doing the simultaneous solar power generation and storage. To realize the aim of the practical application of the PG cells in daily life, the electrical output of these cells has to be further enhanced to a level at least comparable to that of the photovoltaic cells. The present study of the PG cells based on so far unexplored Congo red dye-formaldehyde as a photosensitizer-reductant couple along with efficiency enhancer surfactant reagent (sodium lauryl sulfate) in the sodium hydroxide alkaline medium has shown greatly enhanced cell performance over published results. The present study has shown electrical cell performance of the PG cell as P(pp) 782 μW, i(sc) 3200 μA, V(oc) 1074 mV, and CE 11.02% at artificial and low illumination intensity. The storage capacity (t(0.5)) of the PG cell has been observed in the present study as 120 min in the dark. The study of variation of the different cell fabrication parameters has shown optimum cell performance at an optimal value of these cell fabrication parameters. The most plausible mechanism of the photo-generation of the current in PG cells is also proposed on the basis of observed potential values and published literature.