Hydrogenation-induced surface oxygen vacancies in BiFeO3 nanoparticles for enhanced visible light photocatalytic performance

In recent years, the favorable effect of surface oxygen vacancies on photocatalytic activity has been observed in various metal oxides. In this work, surface oxygen vacancies, for the first time, were introduced into the synthesized BiFeO3 (BFO) nanoparticles by a high pressure hydrogenation process. The formation of surface oxygen vacancies was verified by a variety of characterization techniques. Compared to the pristine BFO, the hydrogenated BFO with surface oxygen vacancies exhibited much higher photocatalytic activities for methyl orange under visible light irradiation. The enhanced photocatalytic activities of the hydrogenated BFO photocatalyst could be attributed to the increased optical absorption, the efficient charge transfer and separation as well as the suppressed recombination of photogenerated electron-hole pairs derived from the induced surface oxygen vacancies in the hydrogenated BFO.