Scheme 2: Photocatalytic reduction of nitrobenzene with benzyl alcohol and TiO2 as photocatalyst to aniline and benzaldehyde using WLEs and subsequent formation of the imine N-benzylidenaniline. Figure 11 (left) shows the formation rate of imine and the degradation rates of nitrobenzene a function of time. The continuous addition of nitrobenzene was carried out with a pump and a specific feed rate of 0.33 mM/min. This allows precise control of the addition rate and thus more accurate control of the reaction conditions. It can be clearly seen that the continuous addition maintained a constant concentration of nitrobenzene in the reactor, which is important to ensure a uniform reaction rate and imine formation. In the first 6 hours, imine formation increases linearly and then only very little imine is formed or the concentration of imine remains constant. A maximum concentration of only 33 mM imine could be formed. This decrease in the reaction rate is accompanied by a strong visible yellow to orange coloration of the reaction solution, due to the product as well as by-products of the reaction. These also absorb the light and thus lead to a lower reaction rate as the photocatalyst receives less photons. Presumably, this can be prevented by using the coated WLE, in which light does not have to pass through the reactants. into the reaction at a rate of 0.1 mM min -1 , which was preciously determined as long-term sustainable reaction rate when using coated WLE. It can be clearly seen that this effects again steady nitrobenzene concentration at approximately 10 mM and that the product imine is formed almost linearly. However, the linear increase in imine formation is not diminished over the course of the reaction at all. Even though the reaction is slower in comparison to the uncoated WLE and suspended photocatalyst, the continuous linear formation thus leads to a higher final concentration of 39 mM. This nicely illustrates the advantage the coating the photocatalyst onto the WLE has over freely suspended photocatalysts when working with strongly light absorbing reactants or products.