当前位置： SCI文献检索 > JOURNAL OF ENVIRONMENTAL MANAGEMENT期刊下所有文献 > Novel rare earth (RE-La, Er, Sm) metal doped ZnO photocatalysts for degradation of Congo-Red dye: Synthesis, characterization and kinetic studies.

Novel rare earth (RE-La, Er, Sm) metal doped ZnO photocatalysts for degradation of Congo-Red dye: Synthesis, characterization and kinetic studies.

Abstract：

:Synthesis and characterization of novel ZnO:RE nanostructured materials doped with 1% rare-earth elements (RE = La, Er, Sm) and their testing for photocatalytic applications were reported. The materials were obtained via electrospining, followed by calcination at 700 °C. The samples were characterized in terms of surface morphology (SEM, TEM), crystalline structure (XRD) and band gap energies. TEM results showed the formation of a unidimensional structure (ZnO) with an average fiber diameter of 600 nm and a morphology consisting of interconnected nanoparticles having dimensions in the range 25-134 nm (ZnO doped with RE). Optical properties were explored by using UV-VIS reflectance spectra and the band gap values were determined with the Kubelka-Munk function (KM) by plotting [F(R∞)hν]2vs. hʋ. The photocatalytic activity was assessed by studying the degradation of a water-soluble anionic dye (Congo-Red) under UV-light irradiation. The data related to photodegradation kinetics were reasonably fitted to the pseudo-first-order kinetic model. Results revealed that the values of the rate constants ranged from 10-3 to 10-2 min-1, depending on the material type and initial dye concentration. In addition, Langmuir-Hinshelwood (LH) model was utilized to explain the kinetics of photodegradation reactions of CR in the presence of (ZnO:Sm) sample. The LH approach suggested that both adsorption and photocatalysis phenomena prevailed in the process of dye removal. Optimal conditions of experiments were determined empirically by employing the gradient method. Thus, a maximal value of color removal efficiency (95.8%) was observed experimentally for the initial dye concentration of 10.7 mg/L and 0.236 g/L catalyst dosage (ZnO:Sm). Furthermore, a successful recovery of the spent catalyst was accomplished by thermal activation.

journal_name

J Environ Manage

journal_title

Journal of environmental management

authors

Pascariu P,Cojocaru C,Olaru N,Samoila P,Airinei A,Ignat M,Sacarescu L,Timpu D

doi

10.1016/j.jenvman.2019.03.060

subject

Has Abstract

pub_date

2019-06-01 00:00:00

pages

225-234

eissn

0301-4797

issn

1095-8630

pii

S0301-4797(19)30363-9

journal_volume

239

pub_type

杂志文章

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Novel rare earth (RE-La, Er, Sm) metal doped ZnO photocatalysts for degradation of Congo-Red dye: Synthesis, characterization and kinetic studies.