Artificial photosynthesis from CO₂ reduction to methane is severely hampered by the kinetically challenging eight-electron transfer process. Accumulated electrons has been demonstrated can decrease this kinetic barrier. However, charge accumulation were mainly reported in several homogenous systems because of its difficulties in heterogenous systems. Here we identify that highly accumulated electrons exist in Au loaded ultrathin MoS₂ under light irradiation, resulting in a superior performance of CO₂ reduction to methane. The selectivity for methane is up to 80% with an average production rate of about 19.38 μmolg^-1 h^-1 in pure water. Further detailed studies reveal that plasmon-excited hot electrons transfer from Au to charged excitons in ultrathin MoS₂ promotes electron accumulation and multi-electron CO₂ reduction kinetics for methane generation. This is further supported by the CO₂ reduction performance of Ag-MoS₂. Along with the vanished accumulated electrons, CO is the main product with a selectivity of 98%.

从动力学上具有挑战性的八电子转移过程严重阻碍了从CO ₂还原成甲烷的人工光合作用。已经证明，积累的电子可以降低这种动力学势垒。然而，由于其在异质系统中的困难，主要在几种同质系统中报告了电荷积累。在这里，我们确定在光照射下，Au负载的超薄MoS _2中存在高度积累的电子，从而将CO ₂还原为甲烷的性能优异。甲烷的选择性高达80％，平均生产率约为19.38μmolg ^-1  h ^-1在纯净水中。进一步的详细研究表明，等离子激发的热电子在超薄MoS _2中从Au转移到带电激子中，可促进电子积累和甲烷生成的多电子CO ₂还原动力学。Ag-MoS ₂的CO ₂还原性能进一步支持了这一点。与消失的累积电子一起，CO是主要产品，选择性达到98％。