Novel photocatalytic conversion of CO2 by vanadium-doped tantalum nitride for valuable solar fuel production
Novel photocatalytic conversion of CO2 by vanadium-doped tantalum nitride for valuable solar fuel production
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DOI：
10.1016/j.jcat.2017.04.020
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发表时间：
2017-08
影响因子：
7.3
通讯作者：
Thi Dieu Cam Nguyen;Thi Phuong Le Chi Nguyen;H. Mai;Van-Duong Dao;Minh Phuong Nguyen;V. Nguyen
中科院分区：
文献类型：
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作者：
Thi Dieu Cam Nguyen;Thi Phuong Le Chi Nguyen;H. Mai;Van-Duong Dao;Minh Phuong Nguyen;V. Nguyen
本研究合成了Ta3N5和V掺杂Ta3N5(V-Ta3N5)催化剂，并在可见光下将CO2转化为有价值的燃料。与Ta2O5相比，合成的Ta3N5和V-Ta3N5对可见光的吸收大大增加，禁带宽度减小。因此，合成的Ta3N5和V-Ta3N5即使在可见光下也能将CO2光催化转化为CO和CH4。存在于Ta3N5晶格中的V掺杂可以作为Ta3N5的价带(N2p)和导带(Ta5d)之间的中间带(V3d)，从而提高光催化剂的电子-空穴分离效率。因此，V-Ta3N5的光催化活性远高于Ta3N5。然而，随着V掺杂率的增加，在Ta3N5表面形成了分布的VN颗粒。形成的颗粒遮盖了到达光催化剂表面的光，导致光催化活性下降。V-Ta3N5的最佳V掺杂比例为2wt.%。结果表明，在可见光下，V-Ta3N5对CO2的光催化还原生成CH4、CO、O2和H_2的速率分别为425、236、1003和56微克−_1CAT/h−_1。
In this study, Ta3N5and V-doped Ta3N5(V–Ta3N5) were synthesized as catalysts for the conversion of CO2into valuable fuels under visible light. As compared with Ta2O5, the synthesized Ta3N5and V–Ta3N5exhibited great increases in visible light adsorption and decreases in band gap energy. Therefore, the synthesized Ta3N5and V–Ta3N5photocatalytically converted CO2into CO and CH4even under visible light. The V dopants, which existed in the Ta3N5lattice, could act as an intermediate band (V3d) between the valence band (N2p) and the conduction band (Ta5d) of the Ta3N5to increase the electron–hole separation efficiency of the photocatalyst. Thus, the photocatalytic activity of V–Ta3N5was much higher than that of Ta3N5. However, an increase in the V doping ratio led the formation of VN particles distributed on the Ta3N5surface. The formed particles eclipsed the light reaching the photocatalyst surface, resulted in a decrease in photocatalytic activity. The optimal V doping ratio in V–Ta3N5was found to be 2 wt.%. As a result, the production rates of CH4, CO, O2, and H2generated from the photocatalytic reduction of CO2by 2 wt.% V–Ta3N5under visible light were 425, 236, 1003, and 56 µmol g−1cat h−1, respectively.