Enhancement of Gas Sensing Performance of Cerium Oxide by Nickel Doping

Rare earth elements exhibit unique physical and chemical properties due to their special electronic structure and are widely employed in applications such as sensors. This paper investigated the impact of nickel doping on the phase, chemical state, and morphological properties of ceria. A comparison of the sensor responses based on cerium oxide-based sensitive materials before and after doping to various organic compounds and hydrogen. This study found that NiO doping promotes the formation of oxygen vacancies in CeO₂ and enhances the concentration of cerium ions in lower valence states. The sensitivity of CeO₂ doped with 1.0% NiO to organic compounds is significantly enhanced, and its response to acetone is markedly higher than that to other organic compounds. Compared with undoped CeO₂-based sensors, the response intensity to acetone is approximately four times higher, and the sensor also exhibits excellent response characteristics toward trace amounts of hydrogen. Research results indicate that nickel doping can effectively increase the concentration of oxygen vacancies in CeO₂, thereby enhancing the material’s response characteristics to specific gases.