Spectral dependencies of the quantum yield of photochemical processes on the surface of nano/micro-particulates of wide-band-gap metal oxides. IV. Theoretical modeling of the activity and selectivity of semiconductor photocatalysts with inclusion of a subsurface electric field in the space charge region

The continuity equation revisited, including a subsurface electric field (E) in the space charge region of the semiconductor photocatalyst is used to assess the effect that the electric field has on the activity and selectivity of the photocatalyst. A mismatch between the experimental spectral dependence of the quantum yield and the corresponding absorption band may be an indicator of the existence of a space charge region in the solid photocatalyst.