Coating TiO2 nanoparticles on the surface of transparent plastic granules using combined electrostatic and heating methods for the photocatalytic degradation of organic pollutants in water

•TiO2 nanoparticles were coated on plastic granules using a simple method.•Mass, temperature and heating time are important parameters in this process.•The mathematical model can explain the coating mechanism very well.•TiO2-coated granules showed good photocatalytic activity.

In this paper, an effective method for superimposing TiO2 nanoparticles on the surface of transparent plastic granules has been reported by combining an electrostatic mechanism and heat treatment. The process was initiated by generating electrostatic charges on plastic granules through the friction mechanism with glass; then, the charged granules were sprinkled with TiO2 nanoparticles. Nanoparticle binding has been improved by heating and softening the granule surface. The coated granules were used to decompose methylene blue (MB) as a wastewater model under solar illumination. The simple theories have been also proposed to explain effect of heating time on coating effectiveness and limitation number of TiO2 particles that can be coated on the granule surface, showing very good agreement between the fitting results and the experimental data.

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