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

Pascariu, Petronela; Cojocaru, Corneliu; Olaru, Niculae; Samoilă, Petrişor; Airinei, Anton; Ignat, Maria; Săcărescu, Liviu; Ţîmpu, Daniel

doi:10.1016/j.jenvman.2019.03.060

Cited by 113 publications

(40 citation statements)

References 54 publications

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“…Previous studies claim that the photocatalytic characteristics of doped ZnO can be enriched with a moderate amount of rare earth elements such as La [23,24,25], Eu [22], Ce [26], and Sm [27]. Among them, La-doped ZnO materials are distinguished by their gas sensitivity and photocatalytic activity, as evidenced by studies in which various synthesis routes have been adopted [28,29,30]. Specifically, Jia et al [28] solvothermally synthesized La 3+ -doped ZnO materials and examined the photocatalytic activities of the product against rhodamine B (RhB) with respect to different doping concentrations.…”

Section: Introductionmentioning

confidence: 99%

Preparation, Characterization and Photocatalytic Activity of La-Doped Zinc Oxide Nanoparticles

et al. 2019

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Lanthanum (La)-doped zinc oxide nanoparticles were synthesized with different La concentrations by employing a gel combustion method using poly(vinyl alcohol) (PVA). The as-synthesized photocatalysts were characterized using various techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), photoluminescence (PL) spectroscopy, and UV–visible absorption spectroscopy. The average size of ZnO nanoparticles decreased from 34.3 to 10.3 nm with increasing concentrations of La, and the band gap, as evaluated by linear fitting, decreased from 3.10 to 2.78 eV. Additionally, it was found that the photocatalytic activity of doped samples, as investigated by using methyl orange dye under visible lights, improved in response to the increase in La concentration. The decomposition of methyl orange reached 85.86% after 150 min in visible light using La0.1Zn0.9O as the photocatalyst.

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Section: Introductionmentioning

confidence: 99%

Preparation, Characterization and Photocatalytic Activity of La-Doped Zinc Oxide Nanoparticles

et al. 2019

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“…The main parameters that can be deduced from the analysis of X-ray diffractograms are summarized in Table 1 , and for their calculation, the diffraction peaks corresponding to the Miller indices (100), (002) and (101) were used. In addition, to estimate the crystallite size (D), the spacing distance between crystallographic planes (d hkl ), the lattice parameters a and c , the Zn–O bond length (L) and the microstrain (ε), the authors utilized the equations described in detail in previous work [ 11 ].…”

Section: Resultsmentioning

confidence: 99%

“…Moreover, this semiconductor material is considered an excellent photocatalyst for the degradation of some organic dyes in wastewater. Many researchers have been trying to improve the photocatalytic properties of ZnO by doping with various metals (La, Sm, Er, Ce, N, Ag, and so on,) [ 10 , 11 , 12 , 13 ], combining with other metal oxides (NiO, CeO 2 , SnO 2 , CuO, CdO, BaTiO 3 , NaNbO 3 , TiO 2 , Bi 2 O 3 , CuFe 2 O 4 ) [ 14 ] or with various carbon-based nanostructures (multi-walled carbon nanotubes (MWCNTs), graphene, graphene oxide) [ 15 , 16 , 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Innovative Low-Cost Carbon/ZnO Hybrid Materials with Enhanced Photocatalytic Activity towards Organic Pollutant Dyes’ Removal

Pascariu¹,

Olaru²,

Rotaru

et al. 2020

Nanomaterials

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A new type of material based on carbon/ZnO nanostructures that possesses both adsorption and photocatalytic properties was obtained in three stages: cellulose acetate butyrate (CAB) microfiber mats prepared by the electrospinning method, ZnO nanostructures growth by dipping and hydrothermal methods, and finally thermal calcination at 600 °C in N2 for 30 min. X-ray diffraction (XRD) confirmed the structural characteristics. It was found that ZnO possesses a hexagonal wurtzite crystalline structure. The ZnO nanocrystals with star-like and nanorod shapes were evidenced by scanning electron microscopy (SEM) measurements. A significant decrease in Eg value was found for carbon/ZnO hybrid materials (2.51 eV) as compared to ZnO nanostructures (3.21 eV). The photocatalytic activity was evaluated by studying the degradation of three dyes, Methylene Blue (MB), Rhodamine B (RhB) and Congo Red (CR) under visible-light irradiation. Therefore, the maximum color removal efficiency (both adsorption and photocatalytic processes) was: 97.97% of MB (C0 = 10 mg/L), 98.34% of RhB (C0 = 5 mg/L), and 91.93% of CR (C0 = 10 mg/L). Moreover, the value of the rate constant (k) was found to be 0.29 × 10−2 min−1. The novelty of this study relies on obtaining new photocatalysts based on carbon/ZnO using cheap and accessible raw materials, and low-cost preparation techniques.

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“…Compared to the M4 sample, which exhibits a decreased slope of the desorption branch meaning a switched desorption mechanism to pore blocking, the M5 sample titania structure seems to contain pores with a narrower neck [23]. The XRD pattern ( Figure 5) proves the formation of the crystalline anatase phase as the main phase [12,17], where the interplanar distance is of d101 = 0.35 nm and the unit cell parameter is of a0 = 0.40 nm (Table 3). The powder morphology has been investigated by SEM imaging (ESI, Figure S2) showing more compact agglomerates in the case of the M5 sample, while the M4 titania sample exhibits fine dispersed powder.…”

Section: Characteristics Of Optimum Materialsmentioning

confidence: 95%

“…In this context, many researchers have focused their efforts on improving several aspects of the photocatalytic processes [11]. For instance, the coupling of the photocatalytic and adsorption process can ameliorate water reclamation and reduce the operational costs [12]. Generally, oxide nanomaterials, such as titanium oxide, zinc oxide [13], copper oxide [14], and graphene oxide [15], have demonstrated their promising potential for photocatalytic degradation of the organic pollutants (phenol, bisphenol, methylene blue, 4-nitrophenol etc.).…”

Section: Introductionmentioning

confidence: 99%

Development of Porous Titania Structure with Improved Photocatalytic Activity: Response Surface Modeling and Multi-Objective Optimization

et al. 2020

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Porous titania was successfully synthesized by an ultrasound-assisted sol-gel route. The synthesis process was empirically modeled and optimized using the response surface methodology (RSM). Input variables adopted for optimization dealt with the weight ratio of precursors (r) and the sonication time (t), representing the used factors in the synthesis procedure. With regard to application, the synthesized TiO2 samples were tested for the photodegradation of two water-soluble organic pollutants under UV–Vis irradiation. Optimal conditions for the efficient pollutants’ photodegradation were found to involve a precursors ratio of 3 and a sonication time of 60 min. Thus, the M5 sample prepared under the founded optimal conditions yielded the maximal removal efficiencies of 98.4% and 46.3% for the photodegradation of CR dye and 2,4-D herbicide, respectively. In addition, the photodegradation kinetics revealed the pseudo first-order rate constants, showing the photodegradation of CR (k1 = 8.86 × 10−2 min−1) by M5 sample is about 1.3-fold faster than the photodegradation of 2,4-D pesticide (k2 = 6.84 × 10−2 min−1).

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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

Cited by 113 publications

References 54 publications

Preparation, Characterization and Photocatalytic Activity of La-Doped Zinc Oxide Nanoparticles

Preparation, Characterization and Photocatalytic Activity of La-Doped Zinc Oxide Nanoparticles

Innovative Low-Cost Carbon/ZnO Hybrid Materials with Enhanced Photocatalytic Activity towards Organic Pollutant Dyes’ Removal

Development of Porous Titania Structure with Improved Photocatalytic Activity: Response Surface Modeling and Multi-Objective Optimization

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