Plasmonic enhanced photoelectrochemical and photocatalytic performances of 1D coaxial Ag@Ag₂S hybrids

Silver (Ag) as one of the most important plasmonic metals has attracted enormous attention due to its distinct surface plasmon resonance (SPR) absorption and high electrical conductivity. Here, we use Ag nanowires (NWs) as the starting material to prepare a series of core-shell structured Ag@Ag₂S composites through an in situ controllable and spontaneous sulfidation process at room temperature. It has been found that the obtained coaxial Ag@Ag₂S hybrid with an optimized ratio of Ag NWs exhibits enhanced photoelectrochemical and photocatalytic performances under visible light irradiation. The underlying contribution of Ag SPR to the enhancement of photoelectrochemical and photocatalytic activities of the Ag@Ag₂S hybrids has been elucidated through wavelength-dependent experiments and transient absorption spectroscopy. The results indicate that the SPR phenomenon of Ag NWs has an influential effect on the photoelectrochemical and photocatalytic activities enhancement of Ag@Ag₂S hybrids, which is often overlooked in the previous reports. An ultrafast electron transfer process (∼350 fs) from the Ag core to the Ag₂S shell has been measured. This work provides a valuable insight into the role of the Ag component in improving the photoelectrochemical and photocatalytic performances of Ag-Ag₂S hybrid nanosystems, which is expected to promote comprehensive understanding and better exploitation of plasmonic Ag in universal photophysical and photochemical systems.