Enhanced photocatalytic water-splitting performance using Fe-doped hierarchical TiO2 ball-flowers

摘要

The photocatalytic water-splitting behavior of hierarchically structured TiO2 ball-flowers with different Fe ion contents was studied, in order to elucidate the effects of Fe doping on their water-splitting performance. It was found that with the increase of Fe doping content, the hydrogen evolution rate increased initially and then decreased. The highest hydrogen evolution of 697 mu mol g(-1) is observed for 2Fe/TiO2, after 4 h of light irradiation, which was five times greater than that in the case of pure TiO2 who has 140 mu mol g(-1) hydrogen evolution after 4 h of light irradiation. This improvement in the water-splitting efficiency owing to optimized Fe doping could be attributed to an enhancement in the visible-light absorption characteristics and an increase in the number of oxygen vacancies, which act as the reaction sites for water splitting.