In recent years, many new reaction systems for light-driven reactions have been developed. However, the industrial implementation of such reactions is still a challenging task. Due to technical limitations such as illumination efficiency or reactor design, photocatalytic processes are still very limited on an industrial scale. Based on the challenges of industrial implementation, a new system for delocalized internal lighting was introduced, the so-called Wireless Light Emitters (WLEs). The technology is based on the principle of resonant inductive coupling (RIC). With the help of the WLEs, reactors can be illuminated internally, which makes them extremely easy to use and scale up. Another benefit of the WLEs is their ability to act as support or carrier for the photocatalysts themselves. While product purification and catalyst recovery of the often nanoparticulate catalyst materials is usually a technical challenge in conventional photoreactors, these problems are eliminated when catalysts are immobilized directly on the WLE. By applying the photocatalyst directly to the Wireless Light Emitters (WLE), a more direct and efficient use of light could be achieved to initiate photocatalytic reactions. This integration offers several potential advantages: by applying the photocatalyst directly to the WLE, the light is directed straight to the catalytic material, which can lead to more efficient use of light as less light is lost through absorption or scattering; an additional advantage of this approach is that light no longer enters the reaction medium, preventing efficiency loss from parasitic light absorption as well as un-wanted photochemical side reactions of reactants, solvents, or products. However, the coating of photocatalysts onto the polymer shells of the WLEs is faced with several challenges, originating in its heat sensitivity and complex geometry. Most studies that produce titanium dioxide coatings use a precursor such as titanium tetraisopropoxide (TTIP) , titanium tetrachloride or tetrabutyl titanate which is subsequently hydrolyzed and heat-treated to convert it to crystalline TiO2 (usually anatase phase). The latter step is not easily applicable in this case as both the polymer shell material as well as the internal electronics are not stable under the typically applied conditions of 400 °C. First attempts used pre-fabricated commercially available P25 TiO2 powder as photocatalyst, to avoid the crystallization step. First, a thin SiO2 layer was deposited on the COP (cyclic olefin copolymer) shell material by RF magnetron sputtering, followed by a thin TiOx layer by reactive DC magnetron sputtering of titanium to act as a primer for better adhesion. The particulate photocatalyst was then coated onto the WLEs by dip coating, which required extensive optimization due to the spherical geometry. This successfully yielded photocatalyst coatings which were proven active in several reactions. However, the layers were not very stable, so that the photocatalyst layer visibly decreased with each use due to abrasion and flaking off. This is presumably due to a missing annealing step which was omitted due to the heat sensitivity of the substrate.