Visible light-operated saccharide–O2 biofuel cell based on the photosensitization of chlorophyll derivative on TiO2 film

The visible light-operated saccharide–O2 biofuel cell consisting of zinc chlorin-e6 (ZnChl-e6) adsorbed on nanocrystalline TiO2 layer coated onto optical transparent conductive glass electrode (OTE) as an anode, platinum-coated OTE as a cathode, and the fuel solution containing sucrose as a saccharide, invertase, glucose dehydrogenase (GDH) and NAD+ is studied as a new type biofuel cell. The short-circuit photocurrent (ISC) and the open-circuit photovoltage (VOC) of this cell are 9.0 μA cm−2 and 415 mV, respectively. The peaks in the photocurrent action spectrum of this cell are observed at 400 and 800 nm and the incident photon-to-current efficiency (IPCE) values at 400 and 800 nm are estimated to be ca. 17.3% and 10.6%. Thus, a new type of visible light-operated saccharide–O2 biofuel cell with the visible and near IR photosensitization of ZnChl-e6 molecules on nanocrystalline TiO2 film electrode is accomplished.