Photocatalysts of 3D Ordered Macroporous TiO2-Supported CeO2 Nanolayers: Design, Preparation, and Their Catalytic Performances for the Reduction of CO2 with H2O under Simulated Solar Irradiation

3D ordered macroporous (3DOM) TiO 2 was synthesized by the method of colloidal crystal template (CCT) using tetrabutyl titanate as precursor solution, and the photocatalysts of the 3DOM TiO 2 -supported CeO 2 nanolayer with different weight ratios of CeO 2 to TiO 2 were successfully prepared by the gas bubbling-assisted membrane precipitation (GBMP) method. The catalysts were systematically characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), mercury intrusion porosimetry (MIP), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS), and photoluminescence spectra (PL). The slow light effect of photonic crystal (3DOM structure) can enhance absorption efficiency of solar irradiation. Moreover, the introduction of CeO 2 nanolayers can effectively extend the photoresponse from UV to visible region and improve the separation of photogenerated electron–hole pairs. The photocatalytic activities for the reduction of CO 2 with H 2 O were evaluated by the production of main product (CO). 3DOM CeO 2 /TiO 2 photocatalysts exhibit high catalytic activity for the photocatalytic reduction of CO 2 with H 2 O under simulated solar irradiation.