Langmuir-Hinshelwood-Hougen-Watson model for the study of photodegradation properties of zinc oxide semiconductor nanoparticles synthetized by Peumus boldus

•ZnO nanoparticles were synthesized using Peumus boldus extract.•The obtained kinetics experimental data were fitted to the LHHW model.•The reaction stage dominates over the adsorption stage in the degradation.•ZnO nanoparticles showed great photocatalytic degradation for MB. In this work zinc oxide nanoparticles (ZnO NPs) are synthesized using Peumus boldus extract for the degradation of methylene blue (MB). The NPs were characterized and the degradation results and experimental data were compared with the Langmuir-Hinshelwood-Hougen-Watson (LHHW) model taking into account an adsorption and reaction steps. The experimental degradation showed 96% degradation in 180 min and according to the model, the mass transfer is present but the reaction stage is dominat for the degradation kinetics. With these results it could be possible to design a larger-scale reactor.