Study on the photocatalytic reaction kinetics in a TiO2 nanoparticles coated microreactor integrated microfluidics device.

For study of the photocatalytic reaction kinetics in a confined microsystem, a photocatalysis microreactor integrated on a microfluidic device has been fabricated using an on-line UV/vis detector. The performance of the photocatalysis microreactor is evaluated by the photocatalytic degradation of Rhodamine B chosen as model target by using commercial titanium dioxide (Degussa P25, TiO2) nanoparticles as a photocatalyst. Results show that the photocatalytic reaction occurs via the Langmuir-Hinshelwood mechanism and the photocatalysis kinetics in the confined microsystem (r = 0.359 min-1) is about 10 times larger than that in macrosystem (r = 0.033 min-1). In addition, the photocatalysis activity of the immobilized TiO2 nanoparticles in the microreactor exhibits good stability under flowing conditions. The present microchip device offers an interesting platform for screening of photocatalysts and exploration of photocatalysis mechanisms and kinetics.