Photoelectrolysis of Water with Natural Mineral TiO2 Rutile Electrodes

Abstract

Natural mineral rutile (TiO2) was studied as anode for photoelectrolysis of water. Both its photoelectrochemical behavior and semiconducting prop-erties are examined in comparison with those of Fe-doped synthetic single crystal TiO2, the latter independently studied to simulate the high impurity content existent in the mineral. The natural and synthetic Fe-doped TiO2 electrodes showed a performance comparable to that of arc-plasma sprayed raw rutile, including a low breakdown potential. Flatband potentials and donor densities were determined from Mott-Schottky plots and evidence for deep and shallow donors is discussed. Photoresponse measurements allowed us to verify the influence of the iron impurities on the performance of such electrodes.