Photocatalytic reduction of hexavalent chromium with illuminated ZnO/TiO2 composite

Naimi-Joubani, Mohammad; Shirzad‐Siboni, Mehdi; Yang, Jae‐Kyu; Gholami, Mitra; Farzadkia, Mahdi

doi:10.1016/j.jiec.2014.07.025

Cited by 127 publications

(30 citation statements)

References 43 publications

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“…7). Similar results are available in the literature (Naimi-Joubani et al 2015;Gezici et al 2016). Using the concept of pH PZC , the surface of PAN/ZnO-TiO 2 n-fib@-Mat will be predominant negatively charged when solution pH > 6.7, while predominant positively charged when pH < 6.7.…”

Section: Effect Of Ph Initial Cr (Vi) Ion Concentration and Contactsupporting

confidence: 81%

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

et al. 2019

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PAN nanofiber-Mat (n-fib@Mat), PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO 2 n-fib@Mat were prepared via electrospinning method. Their high adsorption capacities against dissolved Cr (VI) ions make them as super adsorbents for water treatment. The structure of n-fib@Mat was investigated using XRD, FTIR, SEM, and TEM techniques. The effects of selected parameters such as contact time, initial concentration, and n-fib@Mat amount were assessed in a fixed bed reactor. It was found that the adsorption capacities of PAN n-fib@Mat, PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO 2 n-fib@Mat were pH-dependent and the optimal pH value was between 2.1 and 2.2. The adsorption was rapid, and the equilibrium was reached within 240 min to remove of Cr (VI) ions for PAN/ZnO-TiO 2 n-fib@Mat and 360 min for PAN n-fib@Mat and PAN-ZnO n-fib@Mat. Langmuir isotherms model is preferred for PAN n-fib@Mat, PAN-ZnO n-fib@Mat, and PAN/ZnO-TiO 2 n-fib@Mat for Cr (VI) adsorption. The equilibrium adsorption capacities are 153.85 mg/g, 234.52 mg/g, and 333.43 mg/g for PAN n-fib@Mat, PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO 2 n-fib@Mat for Cr (VI), respectively. The produced n-fib@Mat showed excellent removal ability for Cr (VI). The adsorption kinetic was obeyed pseudo-second-order reaction rate.

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Section: Effect Of Ph Initial Cr (Vi) Ion Concentration and Contactsupporting

confidence: 81%

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

et al. 2019

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“…The modification of TiO 2 induces the enhancement of photocatalytic activity by achieving a more efficient charge separation, increasing the lifetime of the charge carriers, inhibiting the recombination of electron–hole pairs and facilitating interfacial charge transfer to adsorbed substrates [91–92]. In this review we have focused on modification of nanostructured TiO 2 with carbon-based advanced materials, noble metals, oxides and sulfides of transition metals for enhanced photocatalytic activity towards degradation of Cr(VI).…”

Section: Reviewmentioning

confidence: 99%

“…Its better performance was also evident from the consumption of the lowest electrical energy per order of magnitude for photocatalytic reduction of Cr(VI) as compared to that in UV/ZnO and UV/TiO 2 systems [92]. The rate of photocatalytic reduction of Cr(VI) was increased by increasing the photocatalyst dose [154].…”

Section: Reviewmentioning

confidence: 99%

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

Acharya

Naik

Parida

2018

Beilstein J. Nanotechnol.

108

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Cr(VI) exhibits cytotoxic, mutagenic and carcinogenic properties; hence, effluents containing Cr(VI) from various industrial processes pose threat to aquatic life and downstream users. Various treatment techniques, such as chemical reduction, ion exchange, bacterial degradation, adsorption and photocatalysis, have been exploited for remediation of Cr(VI) from wastewater. Among these, photocatalysis has recently gained considerable attention. The applications of photocatalysis, such as water splitting, CO2 reduction, pollutant degradation, organic transformation reactions, N2 fixation, etc., towards solving the energy crisis and environmental issues are briefly discussed in the Introduction of this review. The advantages of TiO2 as a photocatalyst and the importance of its modification for photocatalytic reduction of Cr(VI) has also been addressed. In this review, the photocatalytic activity of TiO2 after modification with carbon-based advanced materials, metal oxides, metal sulfides and noble metals towards reduction of Cr(VI) was evaluated and compared with that of bare TiO2. The photoactivity of dye-sensitized TiO2 for reduction of Cr(VI) was also discussed. The mechanism for enhanced photocatalytic activity was highlighted and attributed to the resultant properties, namely, effective separation of photoinduced charge carriers, extension of the light absorption range and intensity, increase of the surface active sites, and higher photostability. Advantages and limitations for photoreduction of Cr(VI) over modified TiO2 are depicted in the Conclusion. The various challenges that restrict the technology from practical applications in remediation of Cr(VI) from wastewater were addressed in the Conclusion section as well. The future perspectives of the field presented in this review are focused on the development of whole-solar-spectrum responsive, TiO2-coupled photocatalysts which provide efficient photocatalytic reduction of Cr(VI) along with their good recoverability and recyclability.

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“…(2) The coexistence of tetracycline and Cr(VI) ions was conducive to the removal of either constituent contaminant, conrming that the designed Bi 2 WO 6 /N-SrTiO 3 was absolutely superior for the removal of mixed contaminants. Besides, compared with other references regarding the photocatalytic reduction of Cr(VI) ions [42][43][44][45] and the degradation of TC, 46-48 the removal efficiency of the present work showed outstanding advantages (Tables S1 and S2 †).…”

Section: +mentioning

confidence: 58%

A novel strategy to promote photo-oxidative and reductive abilities via the construction of a bipolar Bi₂WO₆/N-SrTiO₃ material

Xing

Chai

et al. 2017

RSC Adv.

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Focusing on holistically promoting both photo-oxidative and reductive abilities, we constructed a novel Bi 2 WO 6 /N-SrTiO 3 composite, which was expected to have excellent properties for the removal of ions. The matched band structures of Bi 2 WO 6 and N-SrTiO 3 were beneficial for inhibiting the recombination of electron-hole pairs and maintaining the redox capacity through a Z-type n-n heterojunction. Such a bipolar design of photo-oxidative and photo-reductive semiconductor nanomaterials is concluded to be highly effective in remediating complicated toxic residual constituents of both unfixed pharmaceuticals and heavy metals in aquatic environments.

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Photocatalytic reduction of hexavalent chromium with illuminated ZnO/TiO2 composite

Cited by 127 publications

References 43 publications

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

A novel strategy to promote photo-oxidative and reductive abilities via the construction of a bipolar Bi₂WO₆/N-SrTiO₃ material

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Photocatalytic reduction of hexavalent chromium with illuminated ZnO/TiO2 composite

Cited by 127 publications

References 43 publications

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

ZnO-TiO2 doped polyacrylonitrile nano fiber-Mat for elimination of Cr (VI) from polluted water

Cr(VI) remediation from aqueous environment through modified-TiO2-mediated photocatalytic reduction

A novel strategy to promote photo-oxidative and reductive abilities via the construction of a bipolar Bi2WO6/N-SrTiO3 material

Contact Info

Product

Resources

About

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

A novel strategy to promote photo-oxidative and reductive abilities via the construction of a bipolar Bi₂WO₆/N-SrTiO₃ material