Effects of morphology on electrocatalytic activity of CeO2 nanomaterials

Morphology of nanomaterials affects their electrocatalytic properties. In this research, CeO2 nanowires and nanosphere samples are prepared by hydrothermal method. Their electrocatalytic properties are evaluated by Cyclic Voltammetry and Linear Sweeping Voltammetry techniques. Even though both samples exhibit similar catalytic ability for oxygen reduction reaction (ORR), the CeO2 nanospheres are more active in promoting oxygen evolution reaction (OER) than its nanowires counterpart. Their molecular characteristics and crystal structures are investigated by X-ray Photoelectron Spectroscopy, Raman and High-Resolution Transmission Electron Microscope, which confirmed that molar concentration of lattice defects on the surface of the CeO2 nanospheres is substantially higher than that on the nanowires surface, leading to the enhanced OER catalytic performance. The research work could provide experimentalists more insights and guidelines in designing optimum morphology of high-performance catalysts for bifunctional electrode application.