Fig. 1. (A) Schematic representation of photo-H2 production with Dmb [NiFeSe]–H2ase (PDB ID : ; 1CC1)14 on CNx–TiO2 suspended in water containing EDTA as a hole scavenger. (B) Irradiation of CNx–TiO2 can result in photo-induced electron transfer by three distinct pathways: (1) TiO2 band gap excitation (2) excitation of CNx (HOMOCNx–LUMOCNx), followed by electron transfer from LUMOCNx into the conduction band of TiO2 (CBTiO2). (3) Charge transfer excitation with direct optical electron transfer from HOMOCNx to CBTiO2. The CBTiO2 electrons generated through pathways 1 to 3 are then transferred via the [Fe4S4] clusters to the [NiFeSe] H2ase active site.
