Sc、B掺杂g-C_(3)N_(4)/TiO_(2)异质结的电子结构与光学性质  

Electronic structure and optical properties of Sc and B Doped g-C_(3)N_(4)/TiO_(2)Heterojunctions

作　　者：聂文峰 刘心中 林熙[2] 李镇宏 林泽宇 NIE Wenfeng;LIU Xinzhong;LIN Xi;LI Zhenhong;LIN Zeyu(School of Ecological Environment and Urban Construction,Fujian University of Technology,Fuzhou 350118,Fujian,China;School of Environmental and Safety Engineering,Fuzhou University,Fuzhou 350108,Fujian,China)

机构地区：[1]福建理工大学生态环境与城市建设学院,福建福州350118 [2]福州大学环境与安全工程学院,福建福州350108

出　　处：《金属功能材料》2024年第2期55-63,共9页Metallic Functional Materials

基　　金：国家重点研发计划(2019YFC1904103)。

摘　　要：采用基于密度泛函理论的第一性原理方法,研究了g-C_(3)N_(4)/TiO_(2)异质结及Sc、B单掺和共掺杂g-C_(3)N_(4)/TiO_(2)异质结的晶胞结构性质、电子性质及光学性质。结果表明:TiO_(2)与g-C_(3)N_(4)两种晶体均具有良好的结构稳定性,g-C_(3)N_(4)单层和TiO_(2)(101)表面相互作用形成范德华异质结,有着带隙较窄、光响应谱带宽、载流子迁移效率高等优点,可有效解决有机污染物降解过程耗能高的问题。掺杂前后的异质结模型合理可行,带隙窄化,有效抑制光生电子-空穴对复合,异质结能带交错促进了电荷的分离以及载流子的迁移。Sc、B的掺杂引入了杂化态,既调节氧化还原能力,又使得带隙进一步减小,其中共掺杂的影响最为明显,为2.178 eV,加速了电荷的传输,体系光吸收边缘红移,在可见光区域响应范围增大,吸光性能增强。The crystal structure,electronic properties,and optical properties of g-C_(3)N_(4)/TiO_(2)heterojunctions,as well as g-C_(3)N_(4)/TiO_(2)heterojunctions doped with Sc and B individually and simultaneously,were investigated using first-principles calculations based on density functional theory.The results show that both TiO_(2)and g-C_(3)N_(4)crystals exhibit good structural stability.The interaction between a single layer of g-C_(3)N_(4)and the TiO_(2)(101)surface forms a van der Waals heterojunction,which has the advantages of a narrow bandgap,a wide spectral response range,and high carrier migration efficiency.This heterojunction can effectively address the issue of high energy consumption in the degradation of organic pollutants.The heterojunction models before and after doping are reasonable and feasible.The bandgap is narrowed,which can effectively suppress the recombination of photo-generated electron-hole pairs.Heterojunction band interleaving promotes charge separation and carrier migration.Doping with Sc and B introduces hybrid states,which not only adjust the redox ability but also further reduce the bandgap.Among them,the effect of simultaneous doping is the most significant,with a bandgap of 2.178 eV.This accelerates charge transfer,shifts the light absorption edge to the red side,increases the response range in the visible light region and enhances light absorption performance.

关 键 词：g-C_(3)N_(4)/TiO_(2)异质结 第一性原理 密度泛函理论 结构性质 电子结构 光学性能 

分 类 号：O469[理学—凝聚态物理] TB34[理学—电子物理学]