In this project we were interested in studying the problem of water pollution: causes, effects on human being lives and the ecosystem, and existing techniques used to reduce its rate while citing the advantages and disadvantages of each of them. This project focused on the use of the photocatalysis process to photodegrade microplastic pollutants by semiconductor photocatalysts into harmless end products such as carbon dioxide and water. Here we report the fabrication of visible light active zinc oxide nanorods (ZnO NRs) using the hydrothermal method, in which Methylene Blue (MB) had been used as an organic model to study the different phtotodegradation aspects. Wherein, the main goal was to study the effect of doping these NRs by N-doped graphene quantum dots-Urea on the absorbance and photoluminescence spectrum of ZnO NRs and on the photodegradation rate of MB.