Adjusting band gap of cerium conversion coating with TiO2 sol and its photocatalysis performance under ultraviolet irradiation

Band gap adjustment is important for the functional properties of cerium conversion coating (CeCC), including the ultraviolet absorption performance and the catalytic capability. To adjust the band gap of CeCC, the TiO2 sol was added drop wise during the CeCC formation process prepared by the dipping approach. The results showed that the band gap energy (Eg) of the CeCC-TiO2 coatings was adjusted from 3.07 eV to 3.51 eV when the TiO2 sol was added. The main technical parameters, primarily the calcining temperature and the post-treatment time, impacted the band gap of the CeCC-TiO2 coatings. The band gap adjustable was used to explore the functional application of the CeCC-TiO2 coatings through photocatalytic experiments. This showed that the increased Eg valued improved the photocatalysis performance of the CeCC-TiO2 coatings because of the stronger reduction capacity and oxidation ability and more OH radicals produced. The CeCC-TiO2 coatings with adjustable Eg values avoid recycling and show an excellent application prospect within environmental cleaning.