A new mesoporous FeBO 3 material having dominant surface magnetism

Abstract

A new mesoporous iron(III) borate material has been synthesized hydrothermally by using supramolecular assembly of cationic (cetyltrimethylammonium bromide, CTAB) or anionic (sodiumdodecyl sulfate, SDS) surfactant as structure directing agent (SDA) during co-condensation of Fe(III) and H 3BO 3 under controlled pH condition. Powder X-ray diffraction, N 2 sorption, HRTEM, FE-SEM-EDS, AAS, FT-IR and UV–Vis spectroscopic tools, Mössbauer and magnetization measurements are used to characterize the nanostructure, porosity, morphology, chemical composition and magnetic properties. Template molecules can be removed from the as-synthesized material by two consecutive HCl–EtOH extraction and the template-free sample showed good surface area with a peak pore width of ca. 2.6 nm. Spectroscopic results suggested the octahedral coordination of Fe(III) in the FeBO 3 framework. Magnetic measurements suggested the coexistence of antiferromagnetic core and the glassy magnetic behavior. The glassy magnetic behavior is ascribed to the dominant surface magnetism for mesoporous FeBO 3. Acid catalytic properties of this material in liquid phase benzylation of mesityline and anisole have been studied.