Tuning the hematite (110) surface properties to enhance its efficiency in photoelectrochemistry

We present the analysis of the role of the substitutional doping on the electronic structure of Fe2O3– hematite – (110) surface. The presence of a heteroatom in different crystallographic positions in the surface layer of hematite influences the band structure– additional donor or acceptor states appear in the band gap depending on the type and charge of the heteroatom. The modifications play a role in altering the absorption coefficient, however to a minor extent in the visible light range. On the other hand, all investigated substitutions seem advantageous for the oxygen evolution reaction, as for this reaction the vacuum potential is located inside the band gap. Additionally, the differences in partial charges and binding energy suggest that the substitution site can play a role in preferential binding of the reaction intermediates