Enhanced PEC Water Splitting Performance of Silver Nanoparticle-Coated CdS Nanowire Photoanodes: The Role of Silver Deposition

In this work, Ag@CdS nanowires (NWs) were fabricated via a facile hydrothermal route and magnetron sputtering. The structure and morphology of the Ag@CdS NWs were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photon spectroscopy. The synthesized Ag@CdS NWs exhibit an enhanced light sensitizing ability due to plasmon-enhanced absorption at the Ag and CdS interface. The Ag@CdS NW photoanode exhibits superior light harvesting and photoelectrochemical performance with an optimal photocurrent density of about 6.15 mA/cm2 at a 0.18 V bias versus the saturated calomel electrode (SCE) and a photocurrent density of about 4.7 times compared to that of the pure CdS NW photoanode. The photochemical conversion efficiency calculated for Ag(45 s)@CdS NWs is found to be 6.6% (potential vs SCE at 0.12 V) compared to 1.28% for CdS NWs at the same potential. The H2 generation obtained from the Ag(45 s)@CdS NW photoanode is 1.8 times higher than that from the pure CdS NW photoanode.