A meso-scale ultrasonic milli-reactor enables gas–liquid-solid photocatalytic reactions in flow

The handling of solid reagents, catalysts and by-products is a daunting challenge in continuous-flow micro- milli-reactors. Suspensions tend to settle over time leading irrevocable clogging the reaction channels. Herein, we describe our efforts develop an ultrasonic milli-reactor which can handle such challenging solid-containing transformations. reactor consists Langevin-type transducer, sonotrode irradiating cylinder, on coiled glass capillary (12.88 mL) was attached. combined with LED illuminating box its efficacy showcased photocatalytic aerobic oxidation benzyl alcohol enabled by TiO2 particles exposed UV-A irradiation. Ultrasound irradiation generates cavitation bubbles causes vigorous oscillation both Taylor bubbles. This improves liquid mixing, gas–liquid mass transfer ensures resuspension settled particles. Moreover, these effects enhance photon absorption semiconductor catalyst, has overall positive effect transformation.