Solar-powered microfluidic photocatalysis

Microfluidics configuration may facilitate greater success for photocatalytic water treatment. In this paper, we designed a planar microfluidic reactor which can overcome the limitations of mass transfer and photon transfer in the previous photocatalytic reactors and improve the photoreaction efficiency by 2 orders of magnitude. The microreactor consisted of two TiO₂-coated glass slides and a microstructured UV-cured NOA81 layer, forming a planar chamber (5 cm × 1.8 cm × 100 μm). In our studies, methylene blue (MB) was used as the model chemical. 3 ml MB solution (3×10^-5 M) was degraded by more than 60% within 15 min using the microfluidic reactor, and the reaction rate constant was found to be 100 times higher than that by using the bulk reactor. The photodegradation performance of the microreactor was also optimized by adjusting the TiO₂ film thickness and flow rate and achieved a reaction rate of 8% s^-1 under solar irradiation.