A facile and green synthesis route to C@LaCO3OH core-shell microspheres using colloidal carbonaceous spheres as template and its by-products as carbon source

C@LaCO₃OH core-shell microspheres have been synthesized by a hydrothermal method using colloidal carbonaceous spheres (CCSs) as template and its by-products as reactant without any other precipitating agent added in the reaction system. The FT-IR and XRD results indicated the successful formation of the well-crystallized LaCO₃OH shell with hexagonal crystal structure on the CCSs’ surface. The morphology and qualitative elemental chemical analysis were characterized by SEM, TEM, and EDS. The effects of co-solvent on the crystallinity of the LaCO₃OH shell were also studied. In addition, PL result showed one emission band centered at 421 nm (λ_ex = 365 nm) of the C@LaCO₃OH microspheres. The UV–visible spectrum was also employed to investigate the optical property of the products. Further, a possible formation mechanism of the core-shell structure was proposed.