基于密度泛函理论的NaTaO_(3)的结构设计及光催化抗菌性能研究

Structural Design and Photocatalytic Antimicrobial Properties of NaTaO_(3) Based on Density Functional Theory

NaTaO_(3)光催化剂因高的化学稳定性和热稳定性,以及环境友好性可以满足不同领域的需求。通过离子掺杂可以调节NaTaO_(3)的电子结构和性能,本文基于密度泛函理论研究了钙钛矿型Na_(0.75)B_(0.25)TaO_(3)(B=Cr,Mn,Fe,Cu,Zn)的电子结构和光学性质,分析了不同过渡金属掺杂对NaTaO_(3)的能带结构和电子态密度的影响。研究发现Cr、Mn、Fe和Zn掺杂使NaTaO_(3)呈现金属性质,Na_(0.75)Cu_(0.25)TaO_(3)则呈现半导体性质并且禁带宽度缩小到1.35 eV。掺杂Cu后会引起新的能级(Cu 3d和Cu 4s)在禁带中出现,这些新的能级位于禁带的中心,会导致禁带向导带移动。此外,Cu掺杂体系的吸收光谱发生了红移并且可将光吸收波长扩展到800 nm。接着,探索了NaTaO_(3)和Na_(0.75)Cu_(0.25)TaO_(3)的光催化抗菌性能,结果表明Cu离子调控后的光催化剂对金黄色葡萄球菌(S.aureus)的杀菌效率为99.99%,并对杀菌机理进行了分析。

The photocatalyst NaTaO_(3),owing to its notable chemical and thermal stability as well as environmental friendliness,emerges as a versatile candidate capable of meeting diverse demands across various fields.Through ion doping,it is feasible to modulate the electronic structure and performance of NaTaO_(3).In this study,employing density functional theory(DFT),electronic structure and optical properties of perovskite-type Na_(0.75) B_(0.25)TaO_(3)(where B=Cr,Mn,Fe,Cu,Zn)were systematically investigated,elucidating the impact of different transition metal dopants on the band structure and electron density of states in NaTaO_(3).The investigation reveals that Cr,Mn,Fe,and Zn doping induces metallic properties,while Na_(0.75) Cu_(0.25)TaO_(3)exhibits semiconductor characteristics,accompanied by a narrowed bandgap of 1.35 eV.The introduction of Cu introduces new energy levels(Cu 3d and Cu 4s)within the bandgap,positioned at its center,resulting in an upward shift of the valence band.Furthermore,the absorption spectra in the Cu-doped system exhibit a redshift,extending the light absorption wavelength up to 800 nm.Subsequently,the photocatalytic antibacterial performance of NaTaO_(3)and Na_(0.75) Cu_(0.25)TaO_(3)was explored,demonstrating a bactericidal efficiency of 99.99%against Staphylococcus aureus(S.aureus)following Cu ion modulation.Finally,an analysis of potential antibacterial mechanisms was undertaken.