Peter Cendula and coworkers have published a thorough paper about the energy diagram of semiconductor/ electrolyte interface for photoelectrochemical cells
Fe2O3 Energy-Band Diagram of Photoelectrochemical (PEC) Water Splitting
P. Cendula, D. Tilley, S. Gimenez, J. Bisquert, M. Schmid, M. Gratzel, and J. O. Schumacher, J. Phys. Chem. C (2014)
A simulation program is available to everyone to design the energy diagram with arbitrary parameters.