To improve the photocatalytic performance of pristine photocatalysts,element doping,construction of composites and fabrication of novel nanostructures are recognized as universal modification methods.These methods hav...To improve the photocatalytic performance of pristine photocatalysts,element doping,construction of composites and fabrication of novel nanostructures are recognized as universal modification methods.These methods have been experimentally verified to be effective in manifold photocatalytic application over various photocatalysts.Density functional theory(DFT)calculation is a powerful and fundamental tool to pinpoint the intrinsic mechanism of the enhanced photocatalytic activity.And it holds the degree of precision ranging from atoms,molecules to unit cells.Herein,recent DFT calculation research progress of modified s-triazine-based graphitic carbon nitride(g-C3N4)systems as photocatalysts is summarized.To specify,we collected information of doping site,formation energy,geometric,and electronic properties.We also discussed the synergistic effect of work function,Fermi level and band edge position on the built-in electric field,transfer route of photogenerated charge carriers and photocatalytic mechanism(traditional typeⅡor direct Z-scheme heterostructure).Moreover,we analyzed the geometric configuration,band structure,and stability of g-C3N4 nanocluster,nanoribbon,and nanotube.Finally,future perspective in the further theoretical revelation of g-C3N4-based photocatalysts is proposed.展开更多
Ag SnO_2是一种较为理想的Ag Cd O替代材料,但由于其中SnO_2近乎绝缘,使得触头材料的接触电阻增大,故改善SnO_2的导电性是急需解决的重大难题。采用基于密度泛函理论的第一性原理赝势法,通过建模的方法,分别建立不同比例(50%、25%、16....Ag SnO_2是一种较为理想的Ag Cd O替代材料,但由于其中SnO_2近乎绝缘,使得触头材料的接触电阻增大,故改善SnO_2的导电性是急需解决的重大难题。采用基于密度泛函理论的第一性原理赝势法,通过建模的方法,分别建立不同比例(50%、25%、16.67%、12.5%、8.34%)La掺杂的SnO_2晶胞模型,并计算分析其晶格常数、电荷布居、能带结构和态密度等性质。结果表明,La掺杂后触头材料中的SnO_2仍属于直接带隙半导体材料,但其禁带宽度变小,载流子浓度变大,使得材料的导电性增强。当La掺杂比为16.67%时导电性最佳。展开更多
基金This work was supported by NSFC(U1705251,21573170,21905219,and 21433007)National Postdoctoral Program for Innovative Talents(BX20180231)+2 种基金Fundamental Research Funds for the Central Universities(WUT:2018IVA089)Innovative Research Funds of SKLWUT(2017-ZD-4)Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(JDGD-201704).
文摘To improve the photocatalytic performance of pristine photocatalysts,element doping,construction of composites and fabrication of novel nanostructures are recognized as universal modification methods.These methods have been experimentally verified to be effective in manifold photocatalytic application over various photocatalysts.Density functional theory(DFT)calculation is a powerful and fundamental tool to pinpoint the intrinsic mechanism of the enhanced photocatalytic activity.And it holds the degree of precision ranging from atoms,molecules to unit cells.Herein,recent DFT calculation research progress of modified s-triazine-based graphitic carbon nitride(g-C3N4)systems as photocatalysts is summarized.To specify,we collected information of doping site,formation energy,geometric,and electronic properties.We also discussed the synergistic effect of work function,Fermi level and band edge position on the built-in electric field,transfer route of photogenerated charge carriers and photocatalytic mechanism(traditional typeⅡor direct Z-scheme heterostructure).Moreover,we analyzed the geometric configuration,band structure,and stability of g-C3N4 nanocluster,nanoribbon,and nanotube.Finally,future perspective in the further theoretical revelation of g-C3N4-based photocatalysts is proposed.
文摘Ag SnO_2是一种较为理想的Ag Cd O替代材料,但由于其中SnO_2近乎绝缘,使得触头材料的接触电阻增大,故改善SnO_2的导电性是急需解决的重大难题。采用基于密度泛函理论的第一性原理赝势法,通过建模的方法,分别建立不同比例(50%、25%、16.67%、12.5%、8.34%)La掺杂的SnO_2晶胞模型,并计算分析其晶格常数、电荷布居、能带结构和态密度等性质。结果表明,La掺杂后触头材料中的SnO_2仍属于直接带隙半导体材料,但其禁带宽度变小,载流子浓度变大,使得材料的导电性增强。当La掺杂比为16.67%时导电性最佳。
