Design of photoelectrochemical cells for the splitting of water and production of fuel

The objective of this research is the design of bioinspired schemes that couple solar energy conversion to the oxidation of water and subsequent use of reducing equivalents to synthesize energy-rich compounds such as hydrogen or fuels based on reduced carbon. To establish the design principles for a tandem, two-junction photochemical cell, we are assembling Grätzel-type photoelectrodes sensitized by pigments inspired by those used in water-oxidizing photosystem II (PSII) and in bacterial photosynthesis. The photoanode, inspired by PSII, will contain a mimic of the water oxidizing side of PSII reaction center. Upon photoexcitation, electrons are injected into semiconductors such as SnO ₂. The photoelectrode model of bacterial reaction centers will be sensitized by low potential naphthalocyanines/phthalocyanines, which absorb light in the near IR region of the spectrum. Upon photoexcitation, these dyes are designed to inject electrons into semiconductors having sufficiently negative conduction bands to effectively drive the reduction of protons to hydrogen.