Band gap engineering of Ba5Nb4O15 for efficient water splitting under visible light
Band gap engineering of Ba5Nb4O15 for efficient water splitting under visible light
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DOI：
10.1016/j.jallcom.2015.05.052
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发表时间：
2015-09
影响因子：
6.2
通讯作者：
Songjie Li;Wenbo Cao;Chengduo Wang;Haiou Qiu
中科院分区：
文献类型：
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作者：
Songjie Li;Wenbo Cao;Chengduo Wang;Haiou Qiu
基于第一性原理和Tran-Blaha修正的Becke-Johnson势，研究了纯的和掺杂的Ba_5Nb_4O_（15）作为太阳能水分解的高效光催化剂.结果表明，新势使Ba 5 Nb 4 O 15的禁带宽度提高到3.81 eV.用阴离子（N，P）或阳离子（Mo）单掺杂在Ba 5 Nb 4 O 15的带边产生一些部分占据态。N-Mo共掺杂和P-Mo共掺杂可以防止部分填充态出现在能带边缘，从而提高光催化效率。共掺杂体系的带边仍然满足自发水裂解的要求。更重要的是，P-Mo共掺杂系统的带隙急剧减小到2.31 eV，处于理想的可见光区。缺陷形成能计算表明，在富氧和贫Nb条件下，P-Mo共掺杂的Ba 5 Nb 4 O 15在能量上是有利的。这表明P-Mo共掺杂的Ba_5Nb_4O_（15）在可见光下具有较高的水分解效率。
Based on first principles with the Tran-Blaha modified Becke-Johnson potential, pure and doped Ba5Nb4O15have been investigated as highly efficient photocatalysts for solar water splitting. The results showed that the calculated band gap of Ba5Nb4O15is improved to 3.81 eV by the new potential. Mono-doping with either anion (N, P) or cation (Mo) creates some partially occupied states at the band edges of Ba5Nb4O15. N–Mo co-doping and P–Mo co-doping can prevent the partially filled states from appearing at band edges and hence enhance the photocatalytic efficiency. The band edges of the co-doped systems still satisfy the requirements for spontaneous water splitting. More importantly, the band gap of P–Mo co-doped system is sharply reduced to 2.31 eV, being in ideal visible light region. The defect formation energy calculations show that P–Mo co-doped Ba5Nb4O15is energetically favorable under O-rich and Nb-poor conditions. These show that P–Mo co-doped Ba5Nb4O15has high efficiency for water splitting under visible light.