Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, College of Chemistry and Chemical Engineering , Inner Mongolia University , Huhhot , Inner Mongolia , PR China.
Inner Mongolia Electric Power Research Institute , Huhhot , Inner Mongolia , PR China.
Inorg Chem. 2018 Jul 16;57(14):8558-8567. doi: 10.1021/acs.inorgchem.8b01287. Epub 2018 Jul 3.
The preferential doping site, visible light response, and redox potential of Fe- and/or La-doped InNbO (INO) were investigated using first-principles density functional theory. Eight designed doping models, including Fe and/or La doping at In or/and Nb sites of INO are constructed, respectively. It was found that Fe-doping and Fe,La-codoping to substitute In into an INO cell are energetically favorable, confirming that the steric hindrance plays a vital role for the selective doping site than the charge of the dopants. Fe doping always formed two impurity bands between the conduction and valence bands, originated from Fe 3d state, inferring the well visible light response. Furthermore, the presence of La has a specific regulation effects for Fe doping although the energy levels of the single La-doped models were completely similar to those of the undoped INO. The electron exchange between La and Fe dopants results in the significant interaction for codoping INO. Importantly, by doping La into INO cell, the redox potentials of Fe-doped INO could be well-regulated. The band potential moved to the more positive energy level of the models Fe-doped at Nb sites, while it shifted to the more negative level if Fe was doped at In site of La-INO. The present investigation may provide the guidance for the designative dopants to construct the photocatalyst with stable, visible response, and good redox performance.
采用第一性原理密度泛函理论研究了 Fe 和/或 La 掺杂的 InNbO（INO）的优先掺杂位置、可见光响应和氧化还原电位。分别构建了 8 种设计的掺杂模型，包括 Fe 和/或 La 掺杂 INO 的 In 或/和 Nb 位。结果表明，Fe 掺杂和 Fe，La 共掺杂取代 INO 中的 In 是能量有利的，这证实了空间位阻对选择性掺杂位置比掺杂剂的电荷起着至关重要的作用。Fe 掺杂总是在导带和价带之间形成两个杂质带，源于 Fe 3d 态，推断出具有良好的可见光响应。此外，尽管单掺 La 的模型的能级完全与未掺杂的 INO 相似，但 La 的存在对 Fe 掺杂具有特定的调节作用。La 和 Fe 掺杂剂之间的电子交换导致共掺杂 INO 之间的显著相互作用。重要的是，通过将 La 掺杂到 INO 单元中，可以很好地调节 Fe 掺杂 INO 的氧化还原电位。能带势向掺杂 Nb 位的 Fe 掺杂模型的更正能级移动，而如果 Fe 掺杂 La-INO 的 In 位，则向更负能级移动。本研究可为设计掺杂剂构建具有稳定、可见光响应和良好氧化还原性能的光催化剂提供指导。
