Search

Plasmon-induced resonance energy transfer (PIRET) plays a key role in enhancing the photoelectrochemical (PEC) performance of metal oxide nanostructures. Herein, photoanodes consisting of α-Fe2O3 nanorod (NR) arrays decorated with Au nanoparticles (NPs) are prepared and optimized to study the PIRET effect. Both the experimental and calculated Ultraviolet-Visible (UV-Vis) spectra indicate that there is a significant near-field coupling between α-Fe2O3 NRs and Au NPs which enable cross-section absorption. The coupling greatly enhances the plasmonic energy transfer from Au NPs to α-Fe2O3 NRs array. The simulated field distribution indicates the Au NPs induce a strong electromagnetic field near the surface of α-Fe2O3 NRs through PIRET. Also, the transient absorption spectroscopy indicates that the direct recombination of photogenerated carriers is significantly limited by the near-field coupling interaction and amplification of the electromagnetic field. The co-catalysts, such as iron oxyhydroxide (FeOOH), are found to have an additional enhancement on the transfer kinetics of holes at the surface. As a result, the photocurrent density of Au/FeOOH-functionalized α-Fe2O3 arrays are about 3.5 times higher than that of pristine α-Fe2O3 NR arrays.