Zhao Can, Chen Qiao-Yue, Zhou Xin-Yuan, Zhao Xu-Cai, Lei Bo-Cheng, Zhang Li-Li, Zhao Jing, Huang Yi-Neng
Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters, College of Physical Science and Technology, Yili Normal University, Yining 835000, China.
Xinjiang Key Laboratory of Clean Conversion and High Value Utilization of Biomass Resources, School of Chemistry and Chemical Engineering, Yili Normal University, Yining 835000, China.
Nanomaterials (Basel). 2025 Aug 28;15(17):1322. doi: 10.3390/nano15171322.
Based on the excellent performance of the K(TaNb)O (KTN) system, this study systematically investigated the mechanism of the influence of metal element (Cd, Sn, Hf) doping on the photocatalytic performance of KTN ferroelectric materials using the density functional theory (DFT) based on first principles. The findings indicate that after metal atom doping, the tolerance factor of doping systems is similar to that of pure KTN crystals, confirming that doping does not compromise its structural stability. However, the ion radius differences caused by doping lead to lattice distortion, significantly reducing the bandgap width. Because the impurity element substituting the Ta site exhibits a lower valence state compared to Ta, holes become the majority carriers, thereby endowing the semiconductor with p-type characteristics. These characteristics effectively suppress electron-hole recombination while enhancing electron transitions. Furthermore, the increase in the dielectric constant of the doped system indicates an enhancement in its polarization capability, which is accompanied by a significant improvement in carrier mobility. The peak of the imaginary part of the dielectric function and the peak of the absorption spectrum both shift towards the low-energy region, indicating that doping has expanded the light response range of the system. Moreover, the effective mass of the holes in all doped systems is significantly higher than that of the electrons, further demonstrating that the introduction of impurities is conducive to hindering the separation of photogenerated electron-hole pairs. These modifications significantly enhance the photocatalytic performance of the systems.
基于K(TaNb)O（KTN）体系的优异性能，本研究采用基于第一性原理的密度泛函理论（DFT），系统地研究了金属元素（Cd、Sn、Hf）掺杂对KTN铁电材料光催化性能的影响机制。研究结果表明，金属原子掺杂后，掺杂体系的容差因子与纯KTN晶体相似，证实掺杂不会损害其结构稳定性。然而，掺杂引起的离子半径差异导致晶格畸变，显著降低了带隙宽度。由于取代Ta位的杂质元素比Ta呈现更低的价态，空穴成为多数载流子，从而赋予半导体p型特性。这些特性有效地抑制了电子-空穴复合，同时增强了电子跃迁。此外，掺杂体系介电常数的增加表明其极化能力增强，同时载流子迁移率显著提高。介电函数虚部的峰值和吸收光谱的峰值均向低能区移动，表明掺杂拓宽了体系的光响应范围。此外，所有掺杂体系中空穴的有效质量均显著高于电子，进一步证明杂质的引入有利于阻碍光生电子-空穴对的分离。这些改性显著提高了体系的光催化性能。
