B、Cu共掺杂单层g-C_(3)N_(4)电子结构及光学性质的第一性原理研究

First principles study on the electronic structure andoptical properties of B and Cu co-doped monolayer g-C_(3)N_(4)

g-C_(3)N_(4)是一种极具潜力的绿色半导体光催化剂,但其带隙较宽,对可见光利用率有限。通过元素掺杂可以有效提高g-C_(3)N_(4)的光催化性能,采用第一性原理方法研究了非金属元素B和金属元素Cu共掺杂对g-C_(3)N_(4)电子结构于光学性质的影响机理,结果表明,B、Cu共掺杂g-C_(3)N_(4)(001)表面的最稳定位点为B占据H位点,而Cu占据N2位点。B、Cu共掺杂相比单一B元素掺杂可以使g-C_(3)N_(4)(001)表面的能隙和功函数进一步下降,Cu元素的加入主要改善了B掺杂的g-C_(3)N_(4)(001)表面的电子导通能力以及对光的捕捉能力,从而提高了光催化活性。

g-C_(3)N_(4) is a highly promising green semiconductor photocatalyst,but its bandgap is wide and its utilization efficiency for visible light is limited.The photocatalytic performance of g-C_(3)N_(4) can be effectively improved through element doping.This paper uses first principles methods to study the mechanism of the influence of non-metallic element B and metallic element Cu co doping on the electronic structure and optical properties of g-C_(3)N_(4).The results indicate that the most stable localization point for B,Cu co-dopped g-C_(3)N_(4)(001)surface is that B occupies the H site,while Cu occupies the N2 site.B.Compared with single B element doping,co doping with Cu can further reduce the energy gap and work function of g-C_(3)N_(4)(001)surface.The addition of Cu mainly improves the electronic conductivity and light capture ability of B-doped g-C_(3)N_(4)(001)surface,thereby enhancing photocatalytic activity.