Most systems rely on the LSPR of isolated metal nanoparticles, randomly deposited on the semiconductor surface, which constraints the photoconversion efficiency due to limited energy transfer possibilities. The synthesis of composite materials that combine plasmonic nanoparticles with semiconductors more effectively, offers a pathway to overcome these limitations. , , , For instance, a study from some of the co-authors has recently shown the advantage of fully embedding Au NPs in a TiO2 thin film to increase the area of interaction between the plasmonic particle surface and the semiconductor. Organizing Au nanoparticles into self-assembled, closely arranged structures is also promising to further enhance the photocatalytic activity through plasmonic coupling of closely separated particles in the assembly, a concept that is already commonly exploited in photothermal and sensing applications. The challenge thus lies in creating a composite structure where the plasmonic nanoparticles are in close proximity to each other as well as to the semiconductor to enhance the energy-transfer efficiency.