Chemical vapor deposition (CVD) through sulfidation of MoO₃ is one of the most important synthesis techniques to obtain large-scale and high-quality two-dimensional (2D) MoS₂. Recently, H₂S precursor is being used in the CVD technique to synthesize 2D MoS₂. Although several studies have been carried out to examine the mechanism of MoS₂ growth in the presence of sulfur and MoO₃ precursors, the growth of MoS₂ in the presence of H₂S precursor has largely remained unknown. In this study, we present a Reactive molecular dynamics (RMD) simulation to investigate the reaction mechanism of MoS₂ from MoO₃ and H₂S precursors. The intermediate molecules formation, the reason behind those formations, and the surface compositions of MoO_xS_yH_z during the initial steps of CVD have all been quantified. Surprisingly, a sudden separation of sulfur atoms from the surface was observed in the H₂S precursor system due to the substantial oxygen evolution after 1660 K. The sulfur detachments and oxygen evolution from the surface were found to have a linear relationship. In addition, the intermediate molecules and surface bonds of MoS₂ synthesized by MoO₃ and H₂S precursors were compared to those of a system using S₂ and MoO₃ precursors. The most stable subsidiary formation from the H₂S precursor was found to be H₂O, whereas in case of S₂ precursor it was SO. These results provide a valuable insight in the formation of large-scale and high-quality 2D MoS₂ by the CVD technique.

_{通过硫化MoO 3}的化学气相沉积（CVD）是获得大规模和高质量二维（2D）MoS ₂的最重要的合成技术之一。最近，H ₂ S 前驱体被用于 CVD 技术以合成 2D MoS ₂。尽管已经进行了几项研究来检查在硫和MoO ₃前体存在下MoS ₂生长的机制，但是在H _{2 S前体存在下MoS 2}的生长在很大程度上仍然是未知的。在这项研究中，我们提出了一个反应分子动力学 (RMD) 模拟来研究MoO中 MoS _{2的反应机理3}和 H ₂ S 前体。中间分子的形成，这些形成背后的原因，以及在 CVD 的初始步骤中 MoO _x S _y H _z的表面成分都已被量化。_{令人惊讶的是，由于在 1660 K 后大量析氧，在 H 2} S 前体系统中观察到硫原子从表面突然分离。发现硫脱离和从表面析出的氧具有线性关系。此外，将由 MoO ₃和 H _{2 S 前体合成的 MoS 2}的中间分子和表面键与使用 S _{2的系统进行了比较。}和 MoO ₃前体。_{发现从 H 2} S 前体形成的最稳定的副产物是 H ₂ O，而在 S ₂前体的情况下是 SO。这些结果为通过 CVD 技术形成大规模和高质量的 2D MoS _{2提供了有价值的见解。}