Z-Scheme Photocatalyst Constructed by Natural Attapulgite and Upconversion Rare Earth Materials for Desulfurization

The Er(3+):CeO(2)/ATP (attapulgite) nanocomposites were prepared by a facile precipitation method. The samples were characterized by various measurements. XRD and TEM showed that Er(3+):CeO(2) nanoparticles were well-crystallized and loaded on the surface of ATP. The visible light was converted into ultraviolet light by Er(3+):CeO(2) as evidenced by upconversion photoluminance (PL) analysis. The mass ratio of Er(3+):CeO(2) to ATP on the desulfurization efficiency was investigated. Results showed that the desulfurization rate reached 87% under 4 h visible light irradiation when the mass ratio was 4:10. The mechanism was put forward as follows. Er(3+):CeO(2) and ATP formed Z-scheme heterostructure intermediated by oxygen vacancy, leading to the enhanced separation of photogenerated charges and preservation of high oxidation-reduction potential, both of which favored for the generation of radicals to oxidize sulfur species.