Qianzhu Mu,Yanfeng Sun,Aiying Guo,Xiazhao Yu,Xiaoyue Xu,Aijun Cai,Xiuping Wang
A series of Fe3O4–TiO2 composites were successfully synthesized using Chlorella pyrenoidosa as a bio-template. C. pyrenoidosa is not only a promising bio-template for obtaining Fe3O4 and TiO2 nanoparticles (NPs) but is also a natural dye sensitizer source that improves the photocatalytic activity of the TiO2 NPs under visible light. The bandgap energy of Fe3O4–TiO2 is narrower than that of TiO2 due to the coupling between the Fe3O4 and TiO2 NPs. The coupling and dye-sensitization lead to the rapid separation and suppressed recombination of electron-hole pairs in Fe3O4–TiO2, which enhances the photocatalytic activity of TiO2 under visible light. The photocatalytic activity of the as-prepared composites was evaluated by degrading a rhodamine B (RhB) aqueous solution under visible-light irradiation. Fe3O4–TiO2 exhibits a high degradation efficiency for RhB, and can be withdrawn from solution easily using an external magnetic field.
Shixin Wei,Qiong Fu,Yang Liu,Qian Ji,Yafei Hou,Laihui Luo,Weiping Li
An enhanced energy storage ability, under a low operating electric field, was achieved in Fe3O4@TiO2-P(VDF-HFP) composite films. The low conductivity TiO2 layer was coated onto the high polarization Fe3O4 to construct Fe3O4@TiO2 core–shell fillers for decreasing filler fraction and alleviating conductivity contrast. For instance, the 2 vol.% Fe3O4@TiO2-P(VDF-HFP) film shows a discharged energy density and energy efficiency of 8.6 J cm−3 and 61.7%, respectively, under a low operating electric field of 261.9 kV mm−1. The coated TiO2 and modified –OH groups not only restrict the adverse effects (such as high conductivity, easy agglomeration, etc) caused by Fe3O4, but also contribute greatly to the improvement of polarization and breakdown strength, leading to a significantly improved energy storage performance. Additionally, the present work might possess great potential applications for energy storage owing to the low filler fraction, simple, and low electric filed operation.