High magnetic field-assisted synthesis of a pine-like hyperbranched structure alpha-Fe2O3 for enhanced magnetic properties and photocatalytic activity

Abstract

The effect of a high magnetic field (HMF) on the synthesis of an iron oxide hyperbranched structure was investigated for the first time. Application of an HMF corresponded to an increased nucleation rate and decreased size. Moreover, the oriented growth in secondary branches was more pronounced; the lattice spacing of the secondary structure decreases significantly. The magnetic properties (and photocatalytic performances toward Congo red) of HMF-α-Fe2O3 were improved. The coercivity increased from a value of 645 Oe to a value of 2716 Oe at 300K, and the degradation rates of Congo red improved from a value of 65% to a value of 85% after 210 min. The enhanced oriented growth, while decreasing the size, is responsible for the improved performance of HMF-α-Fe2O3. This study fills in the gap of research on hyperbranched structures under HMF and is pertinent to preparing multifunctional materials assisted by HMF.