The electronic and optical properties before and after Au decoration on (1 0 $\overline{1}$ 4) surface of dolomite were investigated based on first principles calculations. The electronic structure analysis indicates that the band gap decreases from 4.25 eV (pristine) to 0.81 eV (1 Au decorated case), and the work functions increase from 2.41 eV to 3.53 eV. The density of states analysis revealed that the band gap decrease is mainly attributed to the Au 5d doping states in the forbidden band gap. Moreover, an additional peak located at 310 nm of polarization direction on E//c appears after Au decoration, resulting in the increased absorption intensity in the ultraviolet and visible range. By comparing the redox potential with that of different kinds of pollution gas, it can be found that the Au decorated dolomite might be a good photocatalyst for NO removal. The above results indicate that the Au decorated dolomite could be used in visible light photocatalysis or photovoltaic applications due to its semiconductor characteristics and suitable redox potentials.

（1 0上的Au修饰前后的电子和光学性质 $\overline{\mathrm{1个}}$ 4）基于第一原理计算研究了白云石的表面。电子结构分析表明，带隙从4.25 eV（原始）降低到0.81 eV（1 Au装饰壳），功函从2.41 eV增加到3.53 eV。态密度分析表明，禁带宽度的减小主要归因于Au 5 d禁带隙中的掺杂态。而且，在Au装饰后，在E // c上的偏振方向的310nm处出现了另一个峰，导致在紫外和可见光范围内吸收强度增加。通过将氧化还原电势与各种污染气体的氧化电势进行比较，可以发现用金装饰的白云石可能是去除NO的良好光催化剂。以上结果表明，Au装饰的白云石由于其半导体特性和合适的氧化还原电势而可用于可见光光催化或光伏应用。