Improved photocatalytic performance of gradient reduced TiO2 ceramics with aligned pore channels

This is the authors' abstract. We don't add key points for this paper.

Magnéli, a fascinating sub-stoichiometric titanium oxide phase that contains oxygen vacancies of TiO2, is proposed as a potential photo-electrode for photocatalysis due to its high conductivity and photoelectric conversion efficiency. In this work, partially reduced porous TiO2 ceramics with a graded reduction profile and an aligned pore structure were prepared by carbo-thermal reduction of freeze-cast TiO2 with a range of porosities from 10 to 30 ​vol.%. AC conductivity evaluation revealed that the oxygen vacancies that exist in Magnéli lead to a relatively high AC conductivity of ∼10 ​S/m at 1 ​kHz, as compared to that of the stoichiometric porous TiO2. A maximum photocurrent density and incident photon-to-current efficiency (IPCE) of 9.14 ​mA/cm2 and 40.52% respectively were achieved from the gradient porous Magnéli with a porosity of 30 ​vol.%.