Hydrogen appears as a next-generation clean energy source to replace fossil fuels. One of the most promising ways to produce hydrogen is water splitting using the photoelectrochemical (PEC) cell. Silicon is widely used in this cell due to its viability to absorb light. However, its efficient catalysis and long-term stability remain key challenges due to the corrosion effect. Here we fabricate highly efficient and stable photocathode by integrating crystalline MoS₂ as a catalyst with specially designed Si-based heterojunction cell (n⁺-p-Si) that exhibits ultra-high efficient water reduction in acidic media (0.5 M H₂SO₄) with excellent electrochemical stability. MoS₂ is an efficient low-cost catalyst for hydrogen evolution reaction (HER) and it provides corrosion protection for the Silicon cell. Therefore, thermal decomposition process was used to synthesize few-layers MoS₂ at different concentration, time and temperature. Detailed microscopic and spectroscopic characterizations and the corresponding electrolysis performance based on the synthesized MoS₂ were systematically studied in this work. Based on the results, the best MoS₂ catalyst was deposited on the (n⁺-p-Si) cell to carry out the photoelectrochemical process. The performance characteristics of the photocathode were investigated under 1-sun light illumination. The results showed efficient photocurrent of 38 mA/cm² and onset potential of 0.4 V vs RHE. This study indicates that integration of MoS₂ with heterojunction cell (n⁺-p-Si) is a promising pathway towards efficient and stable hydrogen production.