Interfacial effects of MnOx-loaded TiO2 with exposed {001} facets and its catalytic activity for the photoreduction of CO2

Herein, anatase TiO2 with different percentages of exposed {001} and {101} facets was prepared, and subsequently, Ag and MnOx were co-loaded on these TiO2 facets through a classical photodeposition method; the loaded TiO2 samples were labeled as Ag-TiO2-MnOx (N%), where N% denotes the percentage of the exposed {001} facets. The as-prepared samples were analyzed via scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (DRS), and the photocatalytic reduction of CO2 was carried out. The results showed that Ag-TiO2-MnOx (40%) exhibited the highest photocatalytic activity among the other dual-loaded samples and pure TiO2. The XPS spectra demonstrated that Ti-O-Mn and Ti-O-H bonds were formed at the interfaces of the cocatalyst-TiO2. The PL and VB spectra revealed that the chemical bond (Ti-O-Mn) at the Ag-TiO2-MnOx (40%) interface greatly increased the hole mobility rate and the photoinduced carrier separation efficiency that resulted in higher catalytic activity for the photoreduction of CO2.