Coating of Chlorophylls a and b Enhanced Photoelectrochemical Capacitor Reaction of TiO 2 /MnO 2 Composite Electrode.

We prepared composite electrodes using TiO 2 coated with chlorophylls a and b as photoelectric conversion material and MnO 2 as energy storage material and investigated their photoelectrochemical capacitor properties. The coating with the combination of chlorophylls a and b improved the photoelectric conversion function of TiO 2 , compared with the coating with each alone. Na + adsorption on MnO 2 was enhanced with increasing the chlorophyll coating amount. The reason is that more chlorophylls a and b absorb visible light in different wavelengths to promote an easier photoexcited electron transfer to MnO 2 , just as they improve the efficiency of photosynthesis reactions in nature.