Development of a solar water splitting device requires design of a low-cost, efficient, and non-noble metal compound as alternative to noble metals. Here we will demonstrate that binary cobalt sulfide or ternary cobalt phosphosulfide can function as co-catalyst in phototoelectrochemical hydrogen production. We designed a heterostructure of p-Si and binary cobalt sulfide or ternary cobalt phosphosulfide solar-driven hydrogen production. These two types of co-catalysts successively coupled with p-Si can act as a superior photocathode in solar-driven water splitting reaction.