Rising temperatures and climate variations strain natural and human systems, while an increasing energy gap, heightened by geopolitical tensions, prompts a global shift towards greener energy; 1,2 however, the limited adoption of renewable sources, particularly in hydrogen production, underscores the need to explore alternative methods like emerging photoelectrochemical water-splitting technologies. Antimony selenide (Sb2Se3) garnered attention for solar water splitting, due to its promising characteristics, including a high absorption coefficient (>10 5 cm -1 ), photostability, and cost-effective obtainment and synthesis. This material shows excellent performance and stability when paired with suitable catalysts. Therefore, the search for active, easy-to-prepare, and versatile catalysts is an essential factor for the long-term success of this material. While platinum is the most commonly used catalyst for the hydrogen evolution reaction (HER) due to its high catalytic activity and minimal overpotential, its scarcity and high cost hinder large-scale deployment. As a non-noble-metal substitute, nickel and nickel alloy catalysts offer competitiveness but are typically limited to alkaline media due to corrosion in acidic environments. In contrast, molybdenum sulfide (MoSx) stands out for its excellent stability over a wide pH range , making it a promising HER catalyst for Sb2Se3 and other semiconductor materials such as Cu2O and GaInP. This catalyst can facilitate reactions in highly acidic conditions (pH 0-1) without protective overlayers such as TiO2. Various preparation methods have been employed to maximize the density of the reactive sites of the MoSx catalyst. One promising category of these MoSx catalysts is molybdenum sulfide clusters, which, unlike the electrochemically inert basal planes observed in MoS2, have maximized catalytic activity per molybdenum ion with an increased number of active sites for a given geometric surface area. Furthermore, it has been observed that the efficiency of the photoabsorber is hindered by thicker layers of MoS2. However, a thin layer of the molybdenum clusters could fulfil the catalytic requirements, thereby removing any insulation effects from thicker catalyst layers. Herein, we report the suitability of versatile and easy-to-deposit catalysts directly on Sb2Se3, which include molybdenum sulfide clusters in different configurations, such as [Mo3S4(H2O)9]Cl4 ([Mo3S4] 4+ ) and (NH4)2[Mo3S13]⋅2H2O ([Mo3S13] 2-). These earth-abundant catalysts can provide up to 20 mA cm -2 at -0.3 V versus reversible hydrogen electrode (RHE) with only a few nanometers thick layers, matching the photocurrents obtained with heterogenous cocatalysts such as platinum. The easy deposition and simplicity of these molecular catalysts make them an excellent candidate for translation to other systems such as photocatalytic particles. The stability and loading of these catalysts have been studied using XPS and Raman.