摘要
Oxygen-vacancies(OVs)play significant roles in semiconductor-based photocatalysis,such as elevating light absorption property,photogenerated carries separation efficiency,molecular activation,and photocatalytic activity.However,heat-treatment of semiconductors in dangerous H_(2)atmosphere is usually indispensable for OVs formation.In this work,C-doped Bi_(12)O_(17)C_(12)nanosheets were facially heat-treated in H_(2)O vapor(~2.3 vol%)mixed with Ar at 300℃to in-situ introduce OVs by the proposed reactions of C(s)+H_(2)O(g)→CO(g)+H_(2)(g)and H_(2)(g)+O_(Lattice)→H_(2)O(g)+OV.The formation of OVs,which was confirmed by electron paramagnetic resonance(EPR),can narrow the band gap,and enhance the photogenerated e~-/h~+separation efficiency on Bi_(12)O_(17)C_(12).Moreover,OVs-rich Bi_(12)O_(17)C_(12)nanosheets can facilitate molecular O_(2)activation and produce more reactive oxygen species(ROS),especially~1 O_(2),which greatly improve the NO to NO_(3)~-conversion efficiency with NO removal rate of~63%and NO_(3)~-production selectivity of~92.6%.The present work will bring new insights into the construction and roles of OVs in semiconductor-based photocatalysis.
基金
financially supported by the National Natural Science Foundation of China(Nos.21703075,51872107,52073110,22002047)
Natural Science Foundation of Hubei Province(Nos.2020CFB694,2020CFB394)
Fundamental Research Funds for the Central Universities(Nos.2662020LXPY005,2662019QD018)。
