Photocatalytic activity of Ag/Al2O3–Gd2O3photocatalysts prepared by the sol–gel method in the degradation of 4-chlorophenol

Barrera, A.; Tzompantzi, Francisco; Campa-Molina, J.; Casillas, J.E.; Pérez-Hernández, R.; Ulloa-Godínez, Sandra; Velásquez, Celso; Arenas-Alatorre, J.

doi:10.1039/c7ra12665d

Cited by 69 publications

(24 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Qu et al previously reported that the binding energy of 367.1 eV corresponds to Ag + while those of 368.8∼369.2 eV correspond to Ag 0 at Ag 3d 5/2 of Ag 3d spectra . Our result for the main component of Ag 3d 5/2 was located at 367.2 eV, which can be assigned to Ag + ions . The Ag 3d spectra did not show peaks in the binding energy region assigned to Ag 0 (Figure S6c); i. e., metallic Ag was not observed either.…”

Section: Resultssupporting

confidence: 39%

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

et al. 2019

View full text Add to dashboard Cite

We present a highly active CeO 2 -based catalyst for oxidizing CO in automobile exhaust. This catalyst was systemically designed by co-doping with transition metals (TMs). First, we used density functional theory (DFT) calculations to screen Mn and 13 dopant TMs (periods 4~6 in groups VIII~XI) and their 91 binary combinations for co-doping. As a result, Cu and (Cu, Ag) were found to be the best candidates among the single and binary dopants, respectively. Next, we synthesized CeO 2 nano-particles doped with Cu or (Cu, Ag), then experimentally confirmed that the predicted (Cu, Ag) co-doped CeO 2 showed higher activity than pure CeO 2 and other TM-doped CeO 2 . This was attributed to the easy formation of oxygen vacancies in the lattice of CeO 2 . Our study demonstrates that the use of a rational design of CeO 2 -based catalyst through theoretical calculations and experimental validation can effectively improve the low-temperature catalytic activity of CO oxidation.

show abstract

Section: Resultssupporting

confidence: 39%

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The sol-gel method was selected since this procedure allows for the simultaneous formation of metal oxides [8][9][10][11]. First, a solution with a certain amount of aluminum tri-sec-butoxide (97.0%, Aldrich, St. Louis, MO, USA) and 10 mL of 2-methylpentane 2,4-diol (99.999%, JT Baker, Phillipsburg, USA) as a complexing agent was stirred in a round glass flask for 60 min while the temperature was kept at 70 • C. Thereafter, the temperature was reduced to 50 • C and mixed with a second solution prepared by dissolving neodymium acetylacetonate (99.99%, Aldrich) in toluene (99.999%, Aldrich) at 40 • C. The resulting solution was stirred at 50 • C, then, after 60 min, 10 mL of deionized water was added dropwise to promote the hydrolysis of the aluminum and neodymium reagents to produce a gel.…”

Section: Synthesismentioning

confidence: 99%

“…According to previous reports, the modified surface can be considered a new phase with different properties associated to new surface chemistry and chemical activity [4][5][6]. We have reported that the sol-gel method is suitable to produce γ-Al 2 O 3 with photocatalytic activity to degrade organic pollutants in water [7][8][9], however it is desirable to enhance photocatalytic performance in order to reach a higher conversion in the lowest time. In earlier works, the photocatalytic activity of γ-Al 2 O 3 in the degradation of phenolic compounds has been improved by impregnating noble metal (PdO or'Ag 0 ) onto Al 2 O 3 -Ln 2 O 3 (Ln = Nd or Gd) binary oxides [8,10,11] or by doping Al 2 O 3 -Nd 2 O 3 with the semiconducting ZnO to form Al 2 O 3 -Ln 2 O 3 -ZnO ternary oxides [9].…”

Section: Introductionmentioning

confidence: 99%

“…We have reported that the sol-gel method is suitable to produce γ-Al 2 O 3 with photocatalytic activity to degrade organic pollutants in water [7][8][9], however it is desirable to enhance photocatalytic performance in order to reach a higher conversion in the lowest time. In earlier works, the photocatalytic activity of γ-Al 2 O 3 in the degradation of phenolic compounds has been improved by impregnating noble metal (PdO or'Ag 0 ) onto Al 2 O 3 -Ln 2 O 3 (Ln = Nd or Gd) binary oxides [8,10,11] or by doping Al 2 O 3 -Nd 2 O 3 with the semiconducting ZnO to form Al 2 O 3 -Ln 2 O 3 -ZnO ternary oxides [9]. Although the experimental evidences demonstrated that the photocatalytic activity of γ-Al 2 O 3 enhances with the addition of rare earth oxides, semiconducting oxides, or noble metals, the performance against degradation of drug pollutants in water is still unknown; therefore, we proposed to study the photocatalytic degradation of diclofenac in aqueous medium catalyzed with Al 2 O 3 -Nd 2 O 3 binary oxides and the efficiency related to the Nd 2 O 3 content.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photocatalytic Degradation of Diclofenac Using Al2O3-Nd2O3 Binary Oxides Prepared by the Sol-Gel Method

et al. 2020

View full text Add to dashboard Cite

This paper reports the sol-gel synthesis of Al2O3-Nd2O3 (Al-Nd-x; x = 5%, 10%, 15% and 25% of Nd2O3) binary oxides and the photodegradation of diclofenac activated by UV light. Al-Nd-based catalysts were analyzed by N2 physisorption, XRD, TEM, SEM, UV-Vis and PL spectroscopies. The inclusion of Nd2O3 in the aluminum oxide matrix in the 10–25% range reduced the band gap energies from 3.35 eV for the γ-Al2O3 to values as low as 3.13–3.20 eV, which are typical of semiconductor materials absorbing in the UV region. γ-Al2O3 and Al-Nd-x binary oxides reached more than 92.0% of photoconverted diclofenac after 40 min of reaction. However, the photocatalytic activity in the diclofenac degradation using Al-Nd-x with Nd2O3 contents in the range 10–25% was improved with respect to that of γ-Al2O3 at short reaction times. The diclofenac photoconversion using γ-Al2O3 was 63.0% at 10 min of UV light exposure, whereas Al-Nd-15 binary oxide reached 82.0% at this reaction time. The rate constants determined from the kinetic experiments revealed that the highest activities in the aqueous medium were reached with the catalysts with 15% and 25% of Nd2O3, and these compounds presented the lowest band gap energies. The experimental results also demonstrated that Nd2O3 acts as a separator of charges favoring the decrease in the recombination rate of electron-hole pairs.

show abstract

“…To the best of our knowledge, the photocatalytic activity of the Cu-CuO/ZnO composite for the degradation of phenanthrene has not yet been investigated. The amendment of the physicochemical properties of semiconductors through doping and heterostructures with rare earth metal/metal oxide for the improvement of their photocatalytic activities have been previously reported [28,29]; it is suggested that the increased photocatalytic activities of gadolinium incorporated semiconductor is mainly due to the interfacial charge transfer of its 4f shells and the elimination of electron-hole recombination. Hence, the nanocomposite (NC) of CuO/ZnO with gadolinium was considered for improved photodegradation of phenanthrene in water.…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic activity of Gd2O2CO3·ZnO·CuO nanocomposite used for the degradation of phenanthrene

et al. 2018

View full text Add to dashboard Cite

Multimetal oxides nanocomposite photocatalysts based on Gd 2 O 2 CO 3 •ZnO•CuO were prepared by a co-precipitation method and carefully characterized using a range of analytical techniques. More specifically, analysis by X-ray diffraction and electron microscopies confirmed the identity and quality of the as-synthesized powders. The photocatalytic degradation activities of these nanocomposites towards phenanthrene were then investigated by measuring the effects of catalyst dosage, irradiation time, and oxidant addition. In addition, the pseudo first-order kinetic model was used to determine the rate constant of the degradation reaction. Optimum dosages of 0.6, 0.6, and 0.4 gL −1 were recorded when using CuO, Cu-CuO/ZnO, and Gd 2 O 2 CO 3 •ZnO•CuO, respectively. In addition, the Gd 2 O 2 CO 3 •ZnO•CuO composite exhibited a higher removal efficiency than both Cu-CuO/ZnO and the pure CuO nanoparticles. Furthermore, the addition of oxidants influenced the removal of phenanthrene from solution. Finally, the photocatalytic degradation data followed pseudo first-order kinetics as defined by the Langmuir-Hinshelwood model, which allowed prediction of the faster degradation rate by the Gd 2 O 2 CO 3 •ZnO•CuO nanocomposite. The newly synthesized nanocomposite could therefore be considered for the removal of phenanthrene and related polycyclic aromatic hydrocarbons from contaminated water.

show abstract

Photocatalytic activity of Ag/Al₂O₃–Gd₂O₃photocatalysts prepared by the sol–gel method in the degradation of 4-chlorophenol

Abstract: Ag/Al2O3–Gd2O3 showed high efficacy to photodegradate 4-chlorophenol, the strong interaction between silver nano-particles and micro-particles and Al2O3–Gd2O3 entities favors the decrease in the recombination rate.

Cited by 69 publications

References 64 publications

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

Rational Design of Transition Metal Co‐Doped Ceria Catalysts for Low‐Temperature CO Oxidation

Photocatalytic Degradation of Diclofenac Using Al2O3-Nd2O3 Binary Oxides Prepared by the Sol-Gel Method

Photocatalytic activity of Gd2O2CO3·ZnO·CuO nanocomposite used for the degradation of phenanthrene

Contact Info

Product

Resources

About