Ce‐Doped <scp>ZnO</scp> / <scp> CeO ₂ </scp> Synergy: Defect Engineering and Redox Enhancement for Hybrid Supercapacitor Applications

ABSTRACT Zinc oxide (ZnO) has emerged as a potential candidate for supercapacitors due to good electrical conductivity, cost‐effectiveness, and nontoxicity. However, the drawback lies in its lower specific capacity compared to other metal oxides. To address this limitation, we have added cerium (Ce) as a dopant in ZnO, which simultaneously induces secondary phase CeO 2 in a single step. This unique approach eliminated the need for a complex multistep synthesis and tailored the electrochemical properties of ZnO. The PL and Raman results showed the presence of defects. The CeO 2 phase improved particle connectivity, as seen in SEM, and enhanced redox activity via the Ce +3 /Ce +4 transition. As a result, the Ce‐doped ZnO sample exhibited the highest specific capacity of 748 C/g (207 mAh/g) as compared to pure zinc, which is only 224 C/g (62 mAh/g) at 1 A/g current density. Hence, the effective doping engineering and secondary phase resulted in high‐performance Ce‐doped ZnO electrodes.