Layer-by-layer assembly for photoelectrochemical nanoarchitectonics

A recent increase in the demand for energy and the environmental issues related to the existing energy production processes have necessitated the production of clean and renewable energies using alternative sources, such as solar energy and the development of high-performance photoactive nanomaterials. To this end, another notable challenge in nanotechnology and molecular engineering for the development of photoactive devices is finding suitable ways to assemble various photoactive nanomaterials into a single platform, while maintaining an efficient photocatalytic activity. In this regard, layer-by-layer (LbL) assembly is one of the most versatile nanoscale blending methods to assemble diverse materials on various surfaces through the sequential adsorption of materials with complementary interactions. The photoactive properties of LbL-assembled hybrid electrodes are highly tunable through coupling with diverse groups of photoactive nanomaterials. Although LbL assembly has often been chosen for designing hybrid nanostructures that combine the advantageous features of each constituent, recent studies on photoactive LbL thin films for use in emerging novel nanomaterials are still limited. Therefore, in this mini-review, we introduce the recent progress made in the field of advanced device applications, with a particular focus on photo-electrochemical devices of LbL-assembled thin film electrodes. We anticipate that this review will offer new insights into the synthesis and assembly of various photoactive nanocomponents toward the development of novel photoelectroactive devices and fundamental analysis of the photo-electrochemical properties of thin film electrodes.