High-performance heterometallic photocatalysts afforded by polyoxometalate synthons for efficient H₂ production

MoS₂-based materials have emerged as photoelectric semiconductors characterized by a narrow band gap, high capacity for absorbing visible light, and reduced H₂ adsorption energy comparable to Pt. These attributes render them appealing for application in photocatalytic hydrogen production. Despite these advantages, the widespread adoption of MoS₂-based materials remains hindered by challenges associated with limited exposure to active sites and suboptimal catalytic hydrogen production efficiency. To address these issues, we have designed and synthesized a new class of highly dispersed bimetallic/trimetallic sulfide materials. This was achieved by developing polyoxometalate synthons containing Ni-Mo elements, which were subsequently reacted with thiourea and CdS. The resulting Ni₃S₂-MoS₂ and Ni₃S₂-MoS₂-CdS materials achieve photocatalytic hydrogen production rates of 2770 and 2873 μmol g^-1h^-1, respectively. Notably, the rate of 2873 μmol g^-1h^-1 for Ni₃S₂-MoS₂-CdS surpassed triple (3.23 times) the performance of CdS and nearly sextuple (5.77 times) that of single MoS₂. These materials outperformed the majority of MoS₂-based photocatalysts. Overall, this study introduces a straightforward methodology for synthesizing bimetallic/trimetallic sulfides with enhanced photocatalytic H₂ evolution performance. Our findings underscore the potential of transition metal sulfide semiconductors in the realm of photocatalysis and pave the way for the development of more sustainable energy production systems.