The application of
a novel BiFeO3(BFO)-black TiO2(BTO) composite
(called BFOT) as a photocatalyst for the
degradation of methylene blue is reported. The p–n heterojunction
photocatalyst was synthesized for the first time through microwave-assisted
co-precipitation synthesis to change the molar ratio of BTO in BiFeO3to increase the photocatalytic efficiency of the BiFeO3photocatalyst. The UV–visible properties of p–n
heterostructures showed excellent absorption of visible light and
reduced electron–hole recombination properties compared to
the pure-phase BFO. Photocatalytic studies on BFOT10, BFOT20, and
BFOT30 have shown that they decompose methylene blue (MB) in sunlight
better than pure-phase BFO in 70 min. The BFOT30 photocatalyst was
the most effective at reducing MB when exposed to visible light (97%).
Magnetic studies have shown that BTO is diamagnetic, and the BFOT10
photocatalyst exhibits a very weak antiferromagnetic behavior, whereas
BFOT20 and BFO30 show diamagnetic behavior. This study confirms that
the catalyst has poor stability and weak magnetic recovery properties
due to the non-magnetic phase BTO in the BFO.