For nitrobenzene reduction, a solution containing 10 mM Nitrobenzene (Acros Organics) and 2 g L -1 TiO2 (Aeroxide P25, Evonik Degussa) in argon-saturated isopropanol (VWR) was charged into the reaction vessel. The reaction was stirred using an overhead motor with a 4-blade PEEK stirrer (to avoid metals which would interfere with the electromagnetic field). After starting the reaction by turning on the light source (WLE or external LED), samples were taken at regular intervals. After each sampling the sample was filtered through a PVDF filter (Ø 0.02 µm). The products aniline and acetone were analyzed by GC (Focus GC, Thermo Scientific, column: CP-Chirasil 25 m length, 0.25 µm film thickness, method: starting at 41 °C and heating with 80 K min -1 up to 200 °C, 35 kPa constant pressure). The reduction of nitrobenzene was observed by GC-FID (Trace GC Ultra, Thermo Scientific, column: CS Chromatographie 30 m length, 0.25 µm film thickness, method: 70 °C for 2 min, heating with 10 K min -1 up to 240 °C then 25 K min -1 up to 320 °C, 60 kPa constant pressure). As a figure of merit, initial aniline formation rates were obtained by linear regression, the reaction generally proceeded according to zero-order kinetics up until about 80% conversion.