Photo-assisted SCR removal of NO by upconversion CeO/Pr/attapulgite nanocatalyst.

The emission of nitrogen oxides has caused severe harm to the ecosystem; thus, the development of low-cost and high-efficiency denitrification catalysts and new methods are of great significance. In this work, a co-precipitation method was employed to prepare Pr-doped CeO/attapulgite (CeO/Pr/ATP) nanocomposites. X-ray diffraction (XRD), photoluminance spectroscopy (PL), ultraviolet-visible diffuse reflectance (UV-Vis), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HRTEM) were utilized to characterize the products. Results showed that the CeO/Pr nanoparticles were uniformly coated on the surface of ATP and demonstrated outstanding upconversion effect which converted the visible light to ultraviolet light. The upconversion luminescence of CeO/Pr/ATP was strongest when the molar doping amount of Pr was 1 mol%, and the photo-SCR denitrification achieved the highest of 90% conversion and 95% selectivity when the loading amount of CeO/Pr was 40 wt%. The ATP and CeO/Pr constructed an indirect Z-type heterojunction structure mediated by oxygen vacancy which benefited the separation of charge carriers and enhanced the reduction-oxidation potentials, both are responsible for the remarkable denitrification performance.