Question

How does an oxidized dye molecule in a DSSC get reduced back to its original state?

a. Photons of light reduce the dye molecule.
b. The dye molecule gets reduced by nanocrystalline TiO2.
c. The tunneling of electrons from one electrode to the other reduces the dye.
d. The iodide electrolyte reduces the oxidized dye molecule.
e. Residual water present in the cell will reduce the oxidize dye molecule.

Answer 1

In a DSSC, the oxidized dye molecule gets reduced back to its original state by the iodide ions in the electrolyte, which donate an electron to the dye, completing the circuit and allowing the process to continue.option d is correct answer.

Step-by-step explanation:

An oxidized dye molecule in a dye-sensitized solar cell (DSSC) gets reduced back to its original state through the action of an electrolyte, typically consisting of iodide ions. The process goes as follows:

1. The dye molecule, after capturing a photon of light, gets oxidized by losing an electron.
2. The electron is transferred from the dye to the nanocrystalline TiO2 and then to the anode.
3. At the cathode, the electrolyte containing iodide ions is responsible for replacing the missing electron by reducing the oxidized dye molecule.

This process allows the dye to return to its ground state, ready to absorb another photon and continue generating electricity. Hence, the correct answer is that the iodide electrolyte reduces the oxidized dye molecule.