ZnO nanostructure-based photocatalytic microfluidic reactor for water purification

The impact on environment and on health of different pollutants, especially chemical pollutants, is becoming critical due to their drastic consequences on our main vital resource: water. In recent years, extensive efforts of fundamental research and developing practical processes have been devoted to the polluted water treatment. The semiconductor based photocatalytic process has shown a great potential as an environmental friendly and sustainable treatment technology due to its low-cost, and its ability to decompose the wide spectrum of contaminants in wastewater at room temperature without residual deposits that may require further post-treatment. With high surface/volume ratio, the nanostructured semiconductor shows enhanced photocatalytic efficiency in advancing water and wastewater treatment. Among the photocatalytic materials, ZnO nanostructure is a promising candidate for their easy-controllable synthesis, chemical and thermal stability. On the other hand, its further integration in a microfluidic system can overcome the main limitation of low speed mass transfer during the photo-degradation process of polluted water due to the shorter diffusion length within confined micro-chambers. Here we show a high efficiency microfluidic system decorated inside by ZnO nanostructures leading to a high throughput micro-reactor for water purification.