title: Hydrothermal synthesis and properties of controlled α-Fe2O3 nanostructures in HEPES solution.
abstract: A facile, template-free, and environmentally friendly hydrothermal strategy was explored for the controllable synthesis of α-Fe(2)O(3) nanostructures in HEPES solution (HEPES=2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid). The effects of experimental parameters including HEPES/FeCl(3) molar ratio, pH value, reaction temperature, and reaction time on the formation of α-Fe(2)O(3) nanostructures have been investigated systematically. Based on the observations of the products, the function of HEPES in the reaction is discussed. The different α-Fe(2)O(3) nanostructures possess different optical, magnetic properties, and photocatalytic activities, depending on the shape and size of the sample. In addition, a novel and facile approach was developed for the synthesis of Au/α-Fe(2)O(3) and Ag/α-Fe(2)O(3) nanocomposites in HEPES buffer solution; this verified the dual function of HEPES both as reductant and stabilizer. This work provides a new strategy for the controllable synthesis of transition metal oxide nanostructures and metal-supported nanocomposites, and gives a strong evidence of the relationship between the property and morphology/size of nanomaterials.
authors.affiliation: Key Laboratory for Green Chemical Process of Ministry of Education and School of Chemical Engineering & Pharmacy, Wuhan Institute of Technology, Xiongchu Street, Wuhan, 430073, P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Zhong
authors.initials: Z
authors.lastname: Lu
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Man-Ho
authors.initials: MH
authors.lastname: So
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Che
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
mesh_terms: D002384:Catalysis; D002712:Chlorides / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D006531:HEPES / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D013696:Temperature
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; C000499:ferric oxide; D006531:HEPES; C024555:ferric chloride