Prototyping of Meso- and Microfluidic Devices with Embedded TiO2 Photocatalyst for Photodegradation of an Organic Dye

We present prototyping of meso- and microfluidic photocatalytic devices, functionalized through incorporation of TiO2 nanoparticles in polydimethylsiloxane (PDMS), and comparison of their efficiencies for the degradation of rhodamine B (10(-5) mol/L). The prototyping of the photocatalytic devices involves simple and low-cost procedures, which includes microchannels fabrication on PDMS, deposition and impregnation of TiO2 on PDMS, and, finally, plugging on the individual parts. For the microfluidic device with 13 mu L internal volume, photocatalytic TiO2-PDMS composite was sealed by another PDMS component activated by O-2 plasma (PDMS-TiO2-PDMS). For the mesofluidic device, a homemade polyetheretherketone (PEEK) flow cell with 800 mu L internal volume was screwed on a steel support with a glass slide and the photocatalytic composite. The photocatalytic activities of the devices were evaluated using two different pumping flow systems: a peristaltic pump and a syringe pump, both at 0.05 mL/min under the action of 365 nm ultraviolet (UV) light. The characterization of TiO2-PDMS composite was performed by confocal Raman microscopy, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The photocatalytic microreactor was the most efficient, showing high organic dye photodegradation (88.4% at 12.5 mW/cm(2)).