Influence of N-doping on photocatalytic activity of ZnO nanoparticles under visible light irradiation

N-doped ZnO nano-particles are synthesized by preparing pristine ZnO using sol-gel method and later nitrogenating it by passing nitrogen gas. XRD analysis of sample showed the formation of pure wurtzite phase of ZnO. Optical studies showed a red-shift in the absorbance spectrum after N doping. Raman analysis also supports the formation of defect states in ZnO. The photocatalytic activity of ZnO and N-doped ZnO is evaluated by evaluating rate of degradation of methylene blue and phenol at room temperature under visible light. The N-doped ZnO shows higher photocatalytic activity compared to pristine ZnO and Degussa P-25. The enhancement in the activity is attributed to nitrogen doping induced elevated absorption, high oxygen vacancies and small particle size of the ZnO nanoparticles.