Abstract
Benefitting from a suitable band gap, ceria is an excellent material for UV shielding. By solid solution doping and specific micromorphology, its band gap can be effectively controlled. In this paper, ceria doped with lanthanum via oxalate precipitation is combined with a high-temperature roasting process. The properties of the prepared samples are characterized by UV–Vis diffuse reflectance spectroscopy (DRS), Raman, XRD, FESEM and XPS. The absorption threshold of materials is clearly red-shifted in the ultraviolet band, which originates from the electron-phonon generation. To further reveal the mechanism, the density function theory calculation (DFT) is implemented to study the influence of lanthanum concentrations on ceria’s band gap. It is demonstrated that the band gap can even be narrowed to 2.97 eV by optimizing the sintering temperature and lanthanum-doped concentration. To investigate its improved anti-aging properties under ultraviolet rays, different amounts of 5% lanthanum-doped ceria is mixed with an Al-based coating and then coated on the Q235 steel. Combined with an ultraviolet light irradiation experiment and electrochemical test technology, the corrosion resistance of the modified coatings is evaluated. The coating with 20% La-doped ceria provides the best corrosion resistance performance.
Highlights
Cerium is one of the lanthanide elements, and the reserves in the earth’s crust are rich [1]
Lanthanum doping of the lattice of CeO2 could be defined as the unequal exchange, which results in oxygen vacancy and impairment of lattice integrity
The gap size of face-centered cubes is constructed by cerium and oxygen atoms. Both sizes are smaller than the diameter of the lanthanum ion; the crystal structure of lanthanum-doped ceria is a replacement solid solution
Summary
Cerium is one of the lanthanide elements, and the reserves in the earth’s crust are rich [1]. Cerium oxide has proved its potential in modifying coating properties based on its characteristics of shielding ultraviolet rays and enhancing corrosion resistance. It has been proven that oxygen vacancy doping in cerium oxide can induce the red shift of the absorption threshold under ultraviolet and visible bands [13]. It was found that a lower sintering temperature can produce a certain amount of oxygen vacancies in the microstructure of cerium oxide, while the appropriate doping of lanthanum can introduce doping energy levels. Both methods can reduce the band gap of cerium oxide. The corrosion resistance of the coating was investigated under strong ultraviolet irradiation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
