radical. In addition, we posit that the reaction took place on the surface of ZnO upon the adsorption of the organic pollutants. Our proposition was further confirmed by the presence of carbonaceous species on the surface of ZnO through a combination of spectroscopic probes, i.e. FTIR, SEM–EDX, as well as the deterioration in the BET specific surface area for the used ZnO photocatalyst. The plunge of ZnO’s photodegradation performance was observed in the recyclability test. The performance has plummeted from 50% to 35% in second cycle before stabilizing at 38% in the third cycle. This can be attributed to the blockage of surface area of ZnO by the deposited organic species.