Light-induced hydrogen formation and photo-uptake of oxygen in colloidal suspensions of α-Fe2O3

Abstract

Hydrogen evolution and oxygen reduction as a function of pH of the electrolyte have been investigated for α-Fe₂O₃ powders and colloids by means of a solar simulator. The discrete particle dimensions and surface dynamics of iron oxide seem to be the dominant factors leading to H₂ generation despite the unfavourable position of the conduction band in Fe₂O₃. Evidence is presented that photo-uptake of O₂ occurs in α-Fe₂O₃ suspensions.