Enhanced Photocatalytic Performance of TiO₂@CeO₂ Hollow Structure through Synergetic Surface and Interface Engineering

Abstract In this study, a synergetic structural design is developed to improve the photocatalytic performance of the sub‐micro core–shell hollow sphere (TiO₂@H‐CeO₂). TiO₂@H‐CeO₂ with maximum surface/interface effect is chosen as the substrate and then reacts with different concentrations of Ce(NO₃)₃·6H₂O solutions. Optical properties analysis shows that after the reaction, the band gap of the composite structure and the electron–hole recombination efficiency both decrease while the photodegradation ability is effectively improved. Spectroscopic and microscopic observations reveal two changes in the structure after the reaction. The first is the deposition of CeO₂ nanoparticles that can be observed inside and on the surface of the shell; the second is the doping of Ce³⁺ in the TiO₂ nanoparticles of this shell. The deposition of CeO₂ particles increases the interfacial area between the CeO₂ and TiO₂ and facilitates the corresponding charge transfer. The Ce³⁺ doping in the TiO₂ shell changes the optical properties of TiO₂. Therefore, the improved performance of the composite structure can be attributed to the synergy of different surfaces and interfacial effects caused by the reactions.