Role of Oxygen Defects on the Photocatalytic Properties of Mg-Doped Mesoporous Ta3 N5.
Tantalum nitride (Ta3 N5 ) highlights an intriguing paradigm for converting solar energy into chemical fuels. However, its photocatalytic properties are strongly governed by various intrinsic/extrinsic defects. In this work, we successfully prepared a series of Mg-doped mesoporous Ta3 N5 using a simple method. The photocatalytic and photoelectrochemical properties were investigated from the viewpoint of how defects such as accumulation of oxygen and nitrogen vacancies contribute to the catalytic activity. Our findings suggest that Mg doping is accompanied by an accumulation of oxygen species and a simultaneous elimination of nitrogen vacancies in Ta3 N5 . These oxygen species in Ta3 N5 induce delocalized shallow donor states near the conduction band minimum and are responsible for high electron mobility. The superior photocatalytic activity of Mg-doped Ta3 N5 can then be understood by the improved electron-hole separation as well as the lack of nitrogen vacancies, which often serve as charge-recombination centers.
Department of Chemistry, Tongji University, No. 1239 Siping Road, Yangpu District, Shanghai, China.
Yinghao
Y
Xie
Department of Chemistry, Tongji University, No. 1239 Siping Road, Yangpu District, Shanghai, China.
Yawei
Y
Wang
Department of Chemistry, Tongji University, No. 1239 Siping Road, Yangpu District, Shanghai, China.
Zuofeng
Z
Chen
Department of Chemistry, Tongji University, No. 1239 Siping Road, Yangpu District, Shanghai, China. xxxu@tongji.edu.cn.
Xiaoxiang
0000-0002-5042-9505
X
Xu
D002384:Catalysis; D004563:Electrochemistry; D008274:Magnesium / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D017672:Nitrogen Compounds / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes; D016062:Porosity; D013635:Tantalum / Q000737:chemistry*; D013696:Temperature
D017672:Nitrogen Compounds; D013635:Tantalum; D008274:Magnesium; D010100:Oxygen
Ta3N5; defects; mesoporous; photocatalyst; water splitting