^aPhysics Department, College of Science, Imam Mohammad Ibn Saud Islamic

University (IMSIU), Riyadh 13318, Saudi Arabia

^bDeanship of Scientific Research, Imam Mohammad Ibn Saud Islamic University (IMSIU), P.O. Box 5701, Riyadh 11432, Saudi Arabia

^cChemistry Department, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 13318, Saudi Arabia

^dDepartment of Chemistry, College of Science and Arts, Qassim University, Al- Rass 51921, Saudi

Arabia

In this report, RuO2@ZnO nanostructure was synthesized, characterized, and employed for Congo Red (CR) dye removal from the aquatic phase. The influence of sorption factors contact time, pH, and concentration, was examined. The results indicates the formation of RuO2@ZnO nanostructure with surface area of 21 m2 g- 1 and pore size of 23.5 nm. . The highest amount of Congo red adsorbed by RuO2@ZnO nanostructure was 102.42 mg/g.

Excellent obedience was found between the equilibrium data and the Langmuir model (R2 > 0.9338), whereas the adsorption kinetics was consistent with the pseudo-second-order equation (R2> 0.9999).