Hydrous zirconium nano-particles (HZN) were prepared by combining two suggested methods, hydrolysis from emulsion solutions followed by hydrothermal treatment to obtain the samples in powder form. Characterization of the prepared nano-particles was performed. According to XRF analysis, ZrO2 represents 99.5 wt % as the major component of the prepared samples. The particle size of the prepared nano-particle ranged from 40 to 100 nm determined by TEM analysis. DLS analysis shows the average hydrodynamic diameter is 48.3 nm and 72.06 nm for HZN-1 and HZN-2, respectively. The sorption characteristics of 99Mo on hydrous zirconia nano-particles were investigated using a batch experiment technique. The pseudo-second-order kinetic model showed excellent kinetic data fitting (R2 = 0.99873 and 0.99961 for HZN-1 and HZN-2 nanoparticles, respectively). According to Arrhenius plots, the activation energy of Mo(VI) sorption onto HZN-1 and HZN-2 was found to be 31.8 kJ/mol and 32.5 kJ/mol, respectively. From the Langmuir adsorption isotherm, the maximum sorption capacity is 275.5 and 270.3 mg g-1 for HZN-1 and HZN-2, respectively. Thermodynamic functions, the change of free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) of sorption were also calculated. These parameters show that the sorption process is spontaneous and endothermic at 25–50 ◦C.