Photoelectrochemical water oxidation improved by pyridine N-oxide as a mimic of tyrosine-Z in photosystem II

• Artificial photosynthesis provides a way to store solar energy in chemical bonds with water oxidation as a major challenge for creating highly efficient and robust photoanodes that mimic photosystem II. We report here an easily available pyridine N-oxide (PNO) derivative as an efficient electron transfer relay between an organic light absorber and molecular water oxidation catalyst on a nanoparticle TiO2 photoanode. Spectroscopic and kinetic studies revealed that the PNO/PNO+˙ couple closely mimics the redox behavior of the tyrosine/tyrosyl radical pair in PSII in improving light-driven charge separation via multi-step electron transfer. The integrated photoanode exhibited a 1 sun current density of 3 mA cm−2 in the presence of Na2SO3 and a highly stable photocurrent density of >0.5 mA cm−2 at 0.4 V vs. NHE over a period of 1 h for water oxidation at pH 7. The performance shown here is superior to those of previously reported organic dye-based photoanodes in terms of photocurrent and stability. 

Ämnesord

NATURVETENSKAP  -- Kemi -- Organisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Organic Chemistry (hsv//eng)

Nyckelord

Artificial photosynthesis

Bond strength (chemical)

Electron transitions

Free radical reactions

Oxidation

Pyridine

Redox reactions

Sodium compounds

Solar energy

Titanium dioxide

Electron transfer

Organics

Photo-anodes

Photoelectrochemical water oxidation

Photosystem-II

Pyridine N-oxide

Pyridine N-oxides

Pyridine-N-oxides

Water oxidation

Amino acids

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)