Visible light photocatalytic and magnetic properties of Nd doped Bi2Fe4O9 powders

Nd doped Bi2Fe4O9 powders having compositions Bi2 (1−x) Nd2xFe4O9 (x = 0, 0.02 and 0.05) have been fabricated by a low-temperature solid-state chemical reaction method. Analysis of the X-ray diffraction data reveals that all samples are indexed as a Bi2Fe4O9 orthorhombic structure described by the space group Pbam and lattice structural distortions observed through Nd substitution. The morphology, particle size and chemical compositions of powders have been investigated by using Field Emission Scanning Electron Microscope equipped with energy dispersive X-ray spectroscopy. Enhancement in photocatalytic properties by the degradation of Rhodamine B aqueous solution under visible light irradiation (λ ≥ 420 nm) is found to be associated with the distortion of structure, the variation of morphology, the decrease of average particle size and the reduction of band gap. A weak ferromagnetism with an enhanced saturated magnetization and remnant magnetization at room temperature is observed in Bi1.9Nd0.1Fe4O9, which is quite different from the linear M-H relationship found in Bi2Fe4O9. Our results indicate that the introduction of Nd ions will significantly modify crystal structure, grain size, morphology, and energy band configuration in Bi2Fe4O9 powders, which gives rise to the improvement in its photocatalytic activity and magnetic properties.