Nano-engineered ZnO/CeO2 dots@CNFs for fuel cell application

Abstract

Well-dispersed ZnO(x)CeO2(1−x) nanodots@carbon nanofibers as anode catalysts for the electrooxidation of methanol were synthesized by an easy-controlled template-free method. Their structure and morphology were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FESEM) equipped with rapid EDX (energy dispersive analysis of X-ray). The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by ZnO and CeO2 nanodots. The electrochemical oxidation of methanol on ZnO(x)CeO2(1−x) nanodots@CNFs modified glassy carbon electrode in alkaline solutions was systematically evaluated by cyclic voltammetry (CV) method. A detailed investigation is made for the electrocatalytic oxidation of methanol by varying methanol concentration. The corresponding current densities of ZnO(60%)CeO2(40%) nanodots@CNFs and ZnO(40%)CeO2(60%) nanodots@CNFs were 5.3 and 16.3 mA/cm2, respectively. Moreover, negative onset potential (−50 mV vs. Ag/AgCl) was observed when ZnO(40%)CeO2(60%) nanodots@CNFs were utilized, which is a superior value among the reported non-precious electrocatalysts. These results suggested cheap and effective nanomaterials as non-precious catalyst for DMFCs application and pave the way to further improve the performance in energy and environmental applications.

Keywords

• Carbon nanofibers
• Nanodots
• Electrospinning
• Direct methanol fuel cells
• Negative onset potential