<p>The development of multifunctional nanomaterials is crucial for addressing environmental pollution and heavy metal contamination. In this study, nitrogen-doped zinc oxide (N-ZnO) nanomaterials were synthesized via a simple yet effective method and explored for their dual applications in photocatalytic degradation of methylene blue (MB) dye and electrochemical sensing of lead (Pb²⁺) ions. The crystal studies have demonstrated that the N-ZnO shows reduced particles size and improved surface area. The photocatalytic experiments revealed that N-ZnO achieved an impressive 91% degradation of MB dye under UV light irradiation, significantly outperforming pristine ZnO, which exhibited 76% degradation. The enhanced photocatalytic activity is attributed to nitrogen-induced modifications in the structural features, leading to improved charge carrier separation and extended visible light absorption. Furthermore, N-ZnO demonstrated excellent electrochemical performance for Pb²⁺ detection, exhibiting low charge transfer resistance (R_ct), which facilitates faster electron transport and higher sensitivity. The synergistic effect of nitrogen doping enhances conductivity, increases active surface sites and promotes efficient ion detection. These findings establish N-ZnO as a promising material for environmental remediation, offering a sustainable and efficient platform for both organic pollutant degradation and electrochemical heavy metal sensing.</p>