Synthesis of High Saturation Magnetization Superparamagnetic Fe<sub>3</sub>O<sub>4</sub> Hollow Microspheres for Swift Chromium Removal

Liu, Yubiao; Wang, Yongqiang; Zhou, Shaomin; Lou, Shiyun; Yuan, Lin; Gao, Tao; Wu, Xiaoping; Shi, Xiaojing; Wang, Ke

doi:10.1021/am301239u

Cited by 134 publications

(96 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To augment the active surface area, the crystal size of the magnetic material should be reduced to the nanoscale. Recent studies have shown that magnetite nanoparticles can efficiently adsorb heavy metals, including arsenic, lead, copper and chromium (Hu et al 2006(Hu et al , 2007Liu et al 2012;Vunain et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Martínez

Muñoz‐Bonilla

Mazarío

et al. 2015

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

Well-dispersed magnetite nanoparticles of different sizes between 15 and 43 nm were synthesized by an electrochemical method in a controlled manner by simply changing the synthesis temperature. These nanoparticles were used as a reusable adsorbent to remove Cr(VI) from aqueous solution. The recovery efficiency was found to be highly dependent on environmental parameters, such as temperature and pH. In addition, it was demonstrated that the initial concentrations of both Cr(VI) and magnetite nanoparticles strongly influence the removal capability of these nanomaterials. Remarkably, the nanoparticle size has a key role on the Cr(VI) adsorption efficiency, which gradually increases as the diameter decreases due to the augmentation of the surface area. The low aggregation in the case of small particles that results from the low magnetization saturation values also contributes to the enhancement of the surface area available for Cr(VI) adsorption. In contrast, nanoparticles with larger sizes are more easily manipulated by a magnet, and the efficiency is largely maintained after five cycles. The adsorption process fits the Langmuir isotherm model well, and the reaction was found to follow a pseudo-second-order rate.

show abstract

Section: Introductionmentioning

confidence: 99%

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Martínez

Muñoz‐Bonilla

Mazarío

et al. 2015

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…This is possibly due to the fact that γ-Fe 2 O 3 nanoparticles increase electrostatic adsorption due to the formation of more X-OH 2 + (X=Fe, C) groups. This effect is further translated into an increased capacity for the immobilization and reduction of Cr(VI) [13,14,18,57].…”

Section: Science China Materialsmentioning

confidence: 99%

“…Cr(VI) uptake onto these synthesized magnetic microporous hollow carbon nanospheres is identified as a physicochemical process, including intense electrostatic adsorption [12,55] due to the formation of more X-OH 2 + (X=Fe, C) groups, followed by a redox process in which some of the Cr(VI) is reduced into less toxic Cr(III) [13,14,18,57,61,62]. Meanwhile, the reduced Cr(III) could further conduct complexation with the newly formed oxygen functional groups of the carbon surface.…”

Section: Science China Materialsmentioning

confidence: 99%

Synthesis of magnetic hollow carbon nanospheres with superior microporosity for efficient adsorption of hexavalent chromium ions

et al. 2015

View full text Add to dashboard Cite

[19], polymer-based composites [20][21][22][23], a graphene oxide (GO)-based composite adsorbent [24], and activated carbon [25][26][27][28] have been explored and used in the removal of Cr(VI). Among these adsorbents, carbonaceous porous materials have been successfully used in the removal of Cr(VI) because of their acid and alkali corrosion resistance, excellent thermal and chemical stability and high adsorption capacity for heavy metals [29].In contrast to bulk materials, the high specific surface area of nanoscale materials provides more surface active sites, and good dispersability in solution to help facilitate mass transfer [1,30]. In addition, micropores inherently possess a strong adsorption potential, and can strongly trap and adsorb guest species from the external environment [31]. One can thus envisage that nanosized carbon materials with abundant micropores directly open to the environment could provide fast kinetics and a high adsorption capacity. Furthermore, to easily retrieve these nanosized adsorbents from solution, a functionalized nanocarbon with a magnetic response would be ideal. Although several magnetic carbon adsorbents [12,[31][32][33][34][35][36] have been reported for the removal of chromium, there is still a need to improve such adsorbents to have a high adsorption capacity.It is worth mentioning that recent studies have shown that zinc species is good dynamic molecular porogens to create extra micropores [37][38][39]. These results show that Zn ions turn into ZnO during pyrolysis process. Further temperature increase can lead to the reduction of ZnO nanoparticles in the presence of carbon materials (carbothermal reduction), accompanied by the evaporation of Zn, CO 2 , and CO. The evaporation of the Zn species would create additional nanochannels that contribute to the adMicroporous hollow carbon nanospheres were prepared through the polymerization of 2,4-dihydroxybenzoic acid and formaldehyde in the presence of ammonia and tactfully using chelating zinc species as dynamic porogens during the carbonization step to create extra micropores. The Cr(VI) maximum adsorption capacity of microporous hollow carbon spheres consequently increase from 139.8 mg g −1 of pristine hollow carbon spheres to 199.2 mg g −1 . Owing to the presence of the carboxyl groups in the polymer matrix, Zn 2+ ions can be easily introduced into the hollow polymer spheres through complexation process. During carbonization, high temperature treatment results in the reduction of Zn 2+ to metallic Zn and subsequent evaporation of Zn, consequently forming nanospaces and nanopaths in the carbon shell. As little as 8.6 wt.% Zn 2+ in the polymer matrix can increase the micropore volume by 133% and the specific surface area by 86%. The microporous hollow carbon spheres can be made magnetic by anchoring them to 14.0 wt.% γ-Fe2O3 nanoparticles, thus producing a highly efficient Cr(VI) adsorbent. The maximum adsorption capacity measured was 233.1 mg g −1 , which is significantly higher than other reported carbon-based adsorben...

show abstract

“…3,4 In addition mesoporous iron oxide hollow micro/nanospheres have been investigated as vehicles for controlled drug delivery, 5,6 microwave absorption, 7,8 sensing platforms 9 and waste water treatment. 10,11 Synthesis of iron oxide nanomaterials typically follows one of two synthetic pathways resulting in different nanostructure morphologies, namely nanosheets and ower-like assemblies 3,4,7,13,14,17 and hollow nanospheres and solid nanospheres. 2,9,11,15,16 Differing synthetic routes are obtained by adjusting experimental parameters such as type of precursor, nucleator, surfactant and solvent ratios in addition to reaction time and temperature.…”

Section: Introductionmentioning

confidence: 99%

Temperature controlled shape evolution of iron oxide nanostructures in HMTA media

et al. 2017

View full text Add to dashboard Cite

This work reported an improved approach to the synthesis of iron oxide nanostructures using iron(III) chloride as the precursor and hexamethylenetetramine (HMTA) as the key auxiliary. A range of iron oxide (alkoxide) nanostructures including nanosheets, hierarchical flowers (assembled by thin nanosheets), mesoporous hollow nanospheres and solid nanospheres were obtained only by altering the reaction temperature from 180 C to 240 C in a single synthetic protocol. Supplementary experiments driven by reaction time were designed in order to further clarify the morphological evolution behaviors of these nanostructures, which discovered that the spherical morphology with the size of about 150-200 nm formed from the inside of micro-scaled flower-like clusters gradually by the condensing and weaving of curled nanosheets, suggesting that the hollow nanospheres were obtained consequently by the further condensation of incompact nanospheres with the assistance of the rearrangement of surfactant micelles, followed by the oriented attachment assembly and Ostwald ripening.

show abstract

Synthesis of High Saturation Magnetization Superparamagnetic Fe₃O₄ Hollow Microspheres for Swift Chromium Removal

Cited by 134 publications

References 42 publications

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Synthesis of magnetic hollow carbon nanospheres with superior microporosity for efficient adsorption of hexavalent chromium ions

Temperature controlled shape evolution of iron oxide nanostructures in HMTA media

Contact Info

Product

Resources

About

Synthesis of High Saturation Magnetization Superparamagnetic Fe3O4 Hollow Microspheres for Swift Chromium Removal

Cited by 134 publications

References 42 publications

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Adsorption of chromium(VI) onto electrochemically obtained magnetite nanoparticles

Synthesis of magnetic hollow carbon nanospheres with superior microporosity for efficient adsorption of hexavalent chromium ions

Temperature controlled shape evolution of iron oxide nanostructures in HMTA media

Contact Info

Product

Resources

About

Synthesis of High Saturation Magnetization Superparamagnetic Fe₃O₄ Hollow Microspheres for Swift Chromium Removal