We described a simple experimental set-up for lab work on the photocatalytic degradation of
methylene blue by TiO 2 nanoparticles. The photocatalysis process can be used for many applications.
Treatments for diluted wastewater industries, air purifying in underground car parks, and preventing
fouling on glass surfaces, are some of the potential applications of this phenomenon. The described
experiment is easy to perform and the interpretation can be easily adapted to different levels of
students, from high school students demonstrating their interest in sustainable development, to
students obtaining a Masters in science departments who want to propose a full explanation for all
phenomena of the photocatalytic process. Starting with a description of the experimental set-up, we
analysed the photocatalyst nanoparticles and applied the Langmuir–Hinshelwood model to our
experimental data. Finally we briefly discussed the respective energetic levels of the photocatalyst
semi…