We have performed a density functional theory investigation on the structural and electronic properties of pristine and Nitrogen-doped TiO2 anatase nanoparticles as the adsorbents for removal and degradation of hydrazine molecules in the environment. We have presented the most stable adsorption configurations and examined the interaction of hydrazine molecule with these doped and undoped nanoparticles. Two nitrogen atoms of hydrazine molecule are more reactive than the hydrogen atoms and tend to be adsorbed on the TiO2 nanoparticle. It turns out that the hydrazine molecule is preferentially adsorbed on the active fivefold coordinated titanium atom site of nanoparticle. The insights of the computations include the structural and electronic analyses such as bond lengths/ angles, adsorption energies, density of states (DOSs) and molecular orbitals. It is found that the adsorption of N2H4 on the N-doped nanoparticle is energetically more favorable than the adsorption on the undoped one, representing the higher reactivity of N-doped nanoparticle with hydrazine molecule. It means that the adsorption on the N-doped nanoparticle provides the most stable configurations and consequently the most efficient adsorption processes. Nevertheless, our computational study on the TiO2 anatase nanostructures suggests that the N-doped nanoparticles are highly sensitive than the undoped ones when utilized as detectors or sensors for hydrazine detection.