The study of photocatalytic degradation of a commercial azo reactive dye in a simple design reusable miniaturized reactor with interchangeable TiO2 nanofilm

Abstract

A simple design and low cost miniaturized reactor integrated with interchangeable thin film TiO2 nanolayer was successfully fabricated for the photocatalytic degradation of azo dyes. The TiO2 nanofilms were prepared by sol-gel dip-coating method, while the miniaturized reactor was fabricated on poly methyl methacrylate (PMMA) substrates, using a laser cutting machine. The performance of the miniaturized reactor for the photocatalytic degradation process was investigated for the degradation of a commercial dye (Novacron Red C-2BL). About 98% degradation of the commercial dye was achieved after 100 min in a stopped flow system, and 15% in a continuous flow system. The effect of different operating variables such as pH, initial flow rate, light intensity, layers of the nanoparticles, and temperature on the photocatalytic degradation was studied and the optimum operating conditions were determined to be: inlet flow rate of 0.05 ml/s, pH of 7, UV power 82 W and using a multi-layer of TiO2 thin film in the miniaturized reactor. The reaction kinetics was described as pseudo first order kinetics and rationalized using the Langmuir–Hinshelwood model.