Self-templated synthesis of core-shell Fe3O4@ZnO@ZIF-8 as an efficient visible-light-driven photocatalyst

Facile Preparation of Magnetically Separable Fe3O4/ZnO Nanocomposite with Enhanced Photocatalytic Activity for Degradation of Rhodamine B

“…As shown in Figure 3 b, Fe 3 O 4 /ZnO displays three apparent peaks. The broad absorption band in the range of 3000~3500 cm −1 corresponds to the O-H stretching vibrations of adsorbed water and hydroxyl groups in the samples [ 22 , 25 , 27 ]. In the 1000 to 1600 cm −1 region, the absorption band at ~1633 cm −1 is attributed to the C=O stretching vibration of carboxylic organic acids or the bending vibration of O-H bonds from H 2 O molecules [ 25 , 27 , 29 ], due to the use of zinc acetate, sodium citrate, and sodium hydroxide.…”

“…The broad absorption band in the range of 3000~3500 cm −1 corresponds to the O-H stretching vibrations of adsorbed water and hydroxyl groups in the samples [ 22 , 25 , 27 ]. In the 1000 to 1600 cm −1 region, the absorption band at ~1633 cm −1 is attributed to the C=O stretching vibration of carboxylic organic acids or the bending vibration of O-H bonds from H 2 O molecules [ 25 , 27 , 29 ], due to the use of zinc acetate, sodium citrate, and sodium hydroxide. It also revealed that a few hydroxide radicals were adsorbed on the surface of the composite material, which would make a contribution to high photocatalytic performance for RhB degradation by facilitating the generation of active ·OH radicals.…”

“…This is because Fe 3+ ions acting as capture sites could trap electrons and then be reduced to Fe 2+ . Fe 2+ ions would react with O 2 to generate ·O 2 − and Fe 3+ ions [ 27 , 34 ].…”

“…As an efficient photocatalyst, ZnO has also demonstrated many intriguing qualities, including chemical and physical stability, strong oxidation strength, environmental friendliness, and low price [ 21 , 22 , 23 ]. However, the utilization of ZnO was not fulfilled due to its higher bandgap of ~3.3 eV [ 24 , 25 ], resulting in ZnO only absorbing 5% of the solar energy in UV light and exhibiting low degradation activity for organic pollutants [ 1 ], which limited its practical applications [ 26 , 27 ]. To overcome this drawback and improve the catalytic efficiency, an effective strategy is to utilize metal oxide particles including metal doping, constructing heterojunctions, or nanocomposites to tune the electronic structure of the host, thereby reducing the band gap [ 8 , 10 , 11 , 28 , 29 ].…”

Dual endogenous stimulus-responsive Fe3O4@enzymes@ZIF-8 nanocomposites promote enzymatic circulation chemotherapy

“…Tuning MOF formation on a Fe 3 O 4 core to generate ZIF-8 shells with different thicknesses could be achieved via controlling the size of the magnetic core. 29,30 In order to improve the performance of MOF shells, adsorption, 31 photogenerated carrier ability, 32 intercalation between the Fe 3 O 4 core and the ZIF-8 shell, etc. , could be designed.…”