The design of new magnetic-photocatalyst nanocomposites (CoFe₂O₄–TiO₂) as smart nanomaterials for recyclable-photocatalysis applications

Abstract

Magnetically recyclable 3D CoFe2O4–TiO2 photocatalyst nanocomposite.

Advances in Magnetically Separable Photocatalysts: Smart, Recyclable Materials for Water Pollution Mitigation

“…Three-dimensional (3D) urchin-like TiO 2 , prepared hydrothermally, was decorated with CoFe 2 O 4 using a co-precipitation strategy to yield the nanocomposite photocatalyst CoFe 2 O 4 /TiO 2 with improved photocatalytic properties compared to the individual materials. Upon UV light illumination, the nanocomposite reached 98.9% MB degradation, while 79.9% MB decomposition was realised when the urchin-like TiO 2 was used as the photocatalyst [194]. Moreover, the nanocomposite photocatalyst showed good stability and recyclability, reaching 93.8% MB degradation in the fifth cycles while still maintaining good magnetic properties [194].…”

“…Upon UV light illumination, the nanocomposite reached 98.9% MB degradation, while 79.9% MB decomposition was realised when the urchin-like TiO 2 was used as the photocatalyst [194]. Moreover, the nanocomposite photocatalyst showed good stability and recyclability, reaching 93.8% MB degradation in the fifth cycles while still maintaining good magnetic properties [194]. Impressive photocatalytic activity and versatility was observed for CoFe 2 O 4 /BiOX (X = Cl, Br and I) nanocomposites towards the UV and visible light photocatalytic decomposition of MO, RhB, MB, and their mixture (MO + MB + RhB) [195].…”

“…In all the CoFe 2 O 4 -incorporating nanocomposites, the enhancement in activity could be ascribed to the formation of a heterojunction between CoFe 2 O 4 and the other semiconductor, which allowed efficient charge separation and formation of the reactive species responsible for pollutant degradation. In addition, the presence of CoFe 2 O 4 endowed the nanocomposite photocatalysts with sufficient magnetic sensitivity for easy separation using an external magnetic field [193][194][195][196] [197], Fe,N-TiO 2 /CoFe 2 O 4 [198], and BiOBr/CoFe 2 O 4 [65].…”

Preparation of S–N co-doped CoFe2O4@rGO@TiO2 nanoparticles and their superior UV-Vis light photocatalytic activities

“…Upon UV-Vis irradiation, CoFe 2 O 4 (1.55 eV) with a narrow bandgap energy could be easily excited from the valence band (VB) to the conduction band (CB), inducing the generation of electron-hole pairs (eqn (2)). 24,25,44,45 Notably, the introduction of CoFe 2 O 4 with superparamagnetic behavior was conducive to catalyst recycling. 23,25 For TiO 2 , the co-doping of nitrogen and sulfur into the TiO 2 lattice led to the formation of mid-gap energy levels such as N 2p and S 2p between the valence band (VB) of O 2p and the conduction band (CB) of Ti 3d and narrowed the bandgap energy to 3.08 eV, thereby TiO 2 -S/N can be excited easily by the photons (eqn (3)).…”

Recyclable Magnetic Titania Nanocomposite from Ilmenite with Enhanced Photocatalytic Activity

“…Recently, magnetic titania has gained increasing attention, as it has the advantages of magnetic recovery and excellent photocatalytic properties [15,16,17,18,19]. They can achieve the fast separation and easy recovery of nano-TiO 2 by external magnetic fields, thus preventing the loss of active components and improving the durability of catalysts.…”