论文标题
B和N掺杂到具有MOS $ _2 $的石墨烯和氧化石墨烯异质结构对界面功能和氢进化的相反作用
Contrary Effect of B and N Doping into Graphene and Graphene Oxide Heterostructures with MoS$_2$ on Interface Function and Hydrogen Evolution
论文作者
论文摘要
钼二硫化物（MOS $ _2 $）作为氢生产的高效和低成本的光催化剂吸引了人们的注意，但遭受了低电导率和光子生成荷载载体的高重组率。在这项工作中，我们使用第一原则计算研究了具有石墨烯变体（GVS）（包括石墨烯，氧化石墨烯及其硼和氮和氮的变体）的MOS $ _2 $异质结构。进行石墨烯和氧化石墨烯复合材料之间的系统比较，并阐明B和N掺杂对界面功能和氢进化的相反作用。我们发现，在接口的形成时，从GV侧到MOS $ _2 $层的电子电荷传输，诱导了接口偶极子的创建和工作函数的减少，这在氧化石墨烯复合材料中更为明显。此外，我们的结果表明，N掺杂通过形成供体类型接口状态来增强接口函数，而B兴奋剂通过形成受体型接口状态来降低这些函数。但是，B掺杂的系统比N型系统表现出较低的GIBBS自由能差异GV侧的吸附，这在新的功能性光催化剂的设计中值得考虑。
Molybdenum disulfide (MoS$_2$) attracts attention as a high efficient and low cost photocatalyst for hydrogen production, but suffers from low conductance and high recombination rate of photo-generated charge carriers. In this work, we investigate the MoS$_2$ heterostructures with graphene variants (GVs), including graphene, graphene oxide, and their boron- and nitrogen-doped variants, by using first-principles calculations. Systematic comparison between graphene and graphene oxide composites is performed, and contrary effect of B and N doping on interface function and hydrogen evolution is clarified. We find that upon the formation of the interfaces some amount of electronic charge transfers from the GV side to the MoS$_2$ layer, inducing the creation of interface dipole and the reduction of work function, which is more pronounced in the graphene oxide composites. Moreover, our results reveal that N doping enhances the interface functions by forming donor-type interface states, whereas B doping reduces those functions by forming acceptor-type interface states. However, the B-doped systems exhibit lower Gibbs free energy difference for hydrogen adsorption on GV side than the N-doped systems, which deserves much consideration in the design of new functional photocatalysts.
