Heterogeneous HEA Plasmonics for Superior and Low-Cost Photocatalytic Hydrogen Evolution

Plasmonic nanoparticles (PNP) can hybridize with atomically thin transition metal dichalcogenides (TMD), to dramatically intensify the weak light–matter interaction of those functional semiconductors. Herein, such a heterogeneous system has been designed in the form of gold or high-entropy alloy (HEA) nanoparticles, as well as silicon nanowires (SiNW) and molybdenum disulfide (MoS₂) nanofilms (PNP/SiNW/MoS₂), which exhibits excellent photocatalytic hydrogen evolution reactions (PC-HER). The resonance frequency of the 0D-PNP, the antireflection frequency of 1D-SiNW and the absorption frequency of 2D-MoS₂, match with the visible range simultaneously, for effectively harvesting the free solar energy. In addition, to enable superior efficiency and low cost of PC-HER, there present the following synergetic mechanisms. First, PNP not only show strong electromagnetic enhancement, but also offer photochemical to be a powerful co-catalyst. Next, the SiNW substrate exhibits high antireflection of 95% within the visible light absorption. Besides, an optimal MoS₂ structure that is a hybrid of both 1T and 2H phases was prepared by using reproducible and facile pyrolysis. Moreover, a p–n junction formed at the MoS₂/SiNW interface, facilitates charge separation to further boost the efficiency. In the end, our Au and HEA heterogeneous plasmonics demonstrate exceptional H₂ hydrogen generation rates of 246 and 477.5 mmol g⁻¹ h⁻¹, respectively.