Structure and excellent visible light catalysis of Prussian blue analogues BiFe(CN)6·4H2O

Abstract

Photo-Fenton catalysis with high-efficiency is required for the resolution of environmental pollution. Here, the Prussian blue analogue BiFe(CN)₆·4H₂O with a narrow bandgap (1.63 eV) shows excellent visible light catalysis to decompose organic dyes and tetracycline. The microrod and nanoplate morphologies were successfully synthesized by simple precipitation with different additives. The nanoplates of BiFe(CN)₆·4H₂O show excellent phono-Fenton catalytic activity meaning that RhB can be decomposed within 6 min in the presence of H₂O₂. BiFe(CN)₆·4H₂O exhibits a layered structure, which consists of FeC₆ and BiN₆ coordination polyhedra. The zero field cooling indicated that BiFe(CN)₆·4H₂O has an antiferromagnetic order at low temperatures. Furthermore, the stability of the BiFe(CN)₆·4H₂O catalyst is very good, which has been investigated by various characterizations. The mechanism of the excellent catalysis is related to the crucial role of H₂O₂, which inhibits the recombination of the electron–hole pair and drives the photo-Fenton reaction. Therefore, to treat the wastewater by photo-Fenton catalysis, the present component of BiFe(CN)₆·4H₂O is a promising catalyst candidate.