Figure 2: Electron–proton transfer during photoreduction and discharge process.

(a) Ultraviolet–visible spectrums of starch–H3PMo12O40 (PMo12) solution under photo-irradiation (diluted to 1 mmol l−1 of PMo12). (b) Number of electrons transferred and pH change plots during light irradiation and discharge period (in single cell, room temperature).