Photo-catalytıc degradatıon of ıbuprofen using a microfluidic reactor

The present study reports a fast and efficient chemical decontamination of water using a tree-branched centimetre-scale microfluidic reactor where zinc oxide nanowires (ZnONWs) act as a photocatalyst. Direct growth of ZnONWs on a silicon wafer with a surface of 1.5 × 1.5 cm2 within the microfluidic chamber brings this photocatalytic medium at the very close vicinity of the water flow path, hence minimising the required interaction time to produce efficient purification performance. The phase and the composition of ZnONWs were characterised by XRD and showing an excellent crystallinity. The microreactor consists of two dendritic microchannels for fluid input/output with a chamber volume 30 μl. The performance of microreactor was evaluated by measuring one-pass ibuprofen (IBP) removal yield. It is shown that the IBP concentration changes over time and increased from 25% to 97% with decreasing the IBP concentration. ZnONWs show excellent photocatalytic IBP degradation efficiency (>99%) under UV light in less than 60 seconds in one pass. Therefore, the high surface/volume ratio would significantly improve the mass transfer efficiency. To describe the kinetics of photocatalytic reaction, the model of Langmuir-Hinshelwood is applied in the form of a pseudo first-order model.