Cerium oxide carbonate/nickel hydroxide hybrid nanowires with enhanced performance and stability for urea electrooxidation

Abstract Nickel hydroxide is an attractive catalyst for urea electrooxidation, but its catalytic performance is still unsatisfactory. Herein, a series of cerium oxide carbonate/nickel hydroxide hybrid nanowires were synthesized by a simple one-pot hydrothermal method. The as-prepared hybrid nanowires were characterized by XRD, XPS, SEM, and HRTEM. The introduction of cerium oxide carbonate not only enhanced the structural stability but also promoted the urea oxidation. When used as electrocatalysts for urea oxidation in 1.0 M KOH + 0.33 M urea, the optimized cerium oxide carbonate/nickel hydroxide hybrid nanowires with a Ce/Ni ratio of 0.2 presented the best catalytic performance owing to the improved conductivity, abundant phase interface, and facilitated Ni2+/Ni3+ redox reaction. In addition, the long-term cycling stability was highly improved by the incorporation of cerium oxide carbonate.