Near-field engineering for boosting the photoelectrochemical activity to a modal strong coupling structure

Near-field engineering is considered a significant strategy in constructing plasmonic nanostructures for efficient plasmonic chemistry. We demonstrate interfacial near-field engineering on a Au-NP/TiO 2 /Au-film (ATA) photoanode to improve the water oxidation efficiency. To tailor the near-field distribution, postdeposited Au on an ATA electrode (Au@ATA) is implemented using a facile constant potential electrolysis technique. As a result, the average photocurrent conversion efficiency of Au@ATA is approximately 1.3-fold higher than that of ATA. The near field was tailored to be enhanced at the three-phase boundary of Au-NPs/TiO 2 /H 2 O for efficient water oxidation.