Near-Infrared-Active Periodic Plasmonic Heterostructures Enable High-Efficiency Photoelectrochemical Hydrogen Production

Plasmon-mediatedphotoelectrocatalysis has been regarded as a promisingavenue to boost solar energy conversion. However, the major problemof most plasmonic nanostructures is that they rely heavily on expensivenoble metals (such as Au and Ag), along with the localization of theirsurface plasmon resonance (SPR) in the spatial distribution, whichlimits the improvement of photoelectrochemical performance and hinderstheir practical application. Here, we design a near-infrared (NIR)light-active periodic plasmonic heterostructure composed of semimetallicBi nanoparticles and Bi-3(Se n Te1-n )(2) ternary alloynanowires, which are able to extend the light absorption range andutilize the SPR effect more efficiently. Compare to noble metals,metallic Bi can excite the SPR effect in the whole ultraviolet-to-NIRrange. The periodic heterostructure can alleviate the localizationof the SPR and then improve the charge transfer and redox kineticsthrough the efficient utilization of local electromagnetic fieldsand photothermal heating. In consequence, the photoanode achievesan incident photon-to-current conversion efficiency of 22% at 800nm and a photocurrent density of 13.8 mA cm(-2) at0.85 V-RHE under visible light without any cocatalysts.

Automated summary

In this study, a near-infrared light-active periodic plasmonic heterostructure composed of semimetallic Bi nanoparticles and Bi-3(Se n Te1-n )(2) ternary alloy nanowires was designed to extend the light absorption range and utilize the surface plasmon resonance (SPR) effect more efficiently. Compared to noble metals, metallic Bi can excite the SPR effect in the entire ultraviolet-to-NIR range. The periodic heterostructure can alleviate the localization of the SPR and improve the charge transfer and redox kinetics through the efficient utilization of local electromagnetic fields and photothermal heating. As a result, the photoanode achieves an incident photon-to-current conversion efficiency of 22% at 800nm and a photocurrent density of 13.8 mA/cm² at 0.85 V-RHE under visible light without any cocatalysts.