Fig. 6: Schematic diagram of energy levels of Si-based photocathode.

Solar-driven CO2-to-CH4 conversion on the Si/TiO2 electrode in the absence (a) and presence (b) of [Os] complex.
Solar-driven CO2-to-CH4 conversion on the Si/TiO2 electrode in the absence (a) and presence (b) of [Os] complex.