Nano-MnOx on activated carbon prepared by hydrothermal process for fast and highly efficient degradation of azo dyes

Xu, Lili; Li, Xingfa; Ma, Jianqing; Wen, Yuezhong; Liu, Weiping

doi:10.1016/j.apcata.2014.07.041

Cited by 36 publications

(6 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The degradation of organic compounds by manganese oxides commonly accompany release of Mn(II) from reductive dissolution of manganese oxides [ 19 , 20 ]. Figure 3 shows the dissolution behavior of the three manganese oxides with and without RhB at different pH.…”

Section: Resultsmentioning

confidence: 99%

Decolorization of RhB dye by manganese oxides: effect of crystal type and solution pH

et al. 2015

View full text Add to dashboard Cite

BackgroundOrganic dye pollution in water has become a major source of environmental pollution. Mn(III/IV) oxides have attracted a great deal of attention to remove organic dye pollutants due to their unique structures and physicochemical properties. Numerous studies have reported the removal of dye by various Mn(III/IV) oxides through catalytic degradation and adsorption. The crystalline structures of manganese oxides and solution pH may exert substantial impact on the removal of dyes. However, few studies have focused on the oxidative degradation of RhB dye using Mn(III/IV) oxides with different crystal structures during a spontaneous reaction. In the present study, three manganese oxides with different crystal type (α-MnO2, β-MnO2, and δ-MnO2) were prepared by refluxing process to decolorize RhB dye in various pH solutions.ResultsThe results showed that the decolorization efficiencies of RhB for the three manganese oxides all increase with decrease solution pH. α-MnO2 exhibited highest activity and could efficiently degrade RhB at pH 2–6. The degradation of RhB by β-MnO2 and δ-MnO2 could be observed at pH 2–3, and only little adsorption RhB on manganese oxides could be found at pH 4–6. The UPLC/MS analysis suggests that the decolorization of RhB by manganese oxides consists of three main stages: (1) cleavage of the ethyl groups from RhB molecular to form Rh; (2) further destruction of –COOH and –CNH2 from Rh to form the small molecular substances; (3) mineralization of the small molecular substances into CO2, H2O, NO3− and NH4+.ConclusionsOverall, these results indicate that α-MnO2 may be envisaged as efficient oxidants for the treatment of organic dye-containing wastewater under acid conditions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12932-015-0024-2) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 99%

Decolorization of RhB dye by manganese oxides: effect of crystal type and solution pH

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In this section, the photocatalytic properties of as-prepared g-C 3 N 4 /TiO 2 under visible light are evaluated. And RhB, a typical organic dye which is a common water pollutant and could cause long-term environmental toxicity and short-term public health damage434445, is chosen as the model pollutant. Prior the irradiation under the light source, half hour dark treatment was carried out to realize adsorption equilibrium and eliminate the influence of adsorption on degradation.…”

Section: Resultsmentioning

confidence: 99%

A general nonaqueous sol-gel route to g-C3N4-coupling photocatalysts: the case of Z-scheme g-C3N4/TiO2 with enhanced photodegradation toward RhB under visible-light

Liu

Chen

et al. 2016

Sci Rep

View full text Add to dashboard Cite

The g-C3N4-coupling TiO2 photocatalysts with controllable particle size as well as the interface contact were prepared by a general nonaqueous sol-gel method. The structural and morphological features of g-C3N4/TiO2 were investigated through the X-ray diffraction, Fourier transformed infrared spectra, scanning electron microscopy and transmission electron microscopy, respectively. It is found the TiO2 nanoparticles with a size of 7.3 ± 1.6 nm are uniformly anchored on the surface of the g-C3N4 nanosheets in isolation. The photocatalytic properties of as-prepared g-C3N4/TiO2 were tested by degradation of Rhodamine B (RhB) under visible light, and an enhanced activity is observed. The mechanism of the enhanced activity was further investigated through N2 adsorption-desorption isotherms, UV-vis spectra, photoluminescence spectra, photoelectrochemical measurements, radical trapping experiments and X-ray photoelectron spectroscopy. Furthermore, the photocatalytic performances of obtained g-C3N4/TiO2 under sunlight were also evaluated in aspects of degradation efficiency and stability. The results indicate that the obtained g-C3N4/TiO2 is one promising photocatalyst for practical applications. The study of as-prepared g-C3N4/TiO2 also implies that the present method could be a general route of g-C3N4-coupling photocatalysts.

show abstract

“…6, it is believed that this kinetic model provides the most accurate description of the adsorption of Annona reticulata-chitosan isomers. Azo dye demonstrated a higher removal rate and adsorption loading compared to other isomers [77]. In some situations, the presence of methyl groups may speed up clearance.…”

Section: Sem Analysismentioning

confidence: 94%

Valorization of Annona reticulata biochar by chitosan for the adsorption of Azo dye from Textile effluent

2023

Global NEST: The International Journal

View full text Add to dashboard Cite

<p>Azo dye is a synthetic aromatic dye which are direct dye frequently used in textile industry to colour fibres. It also contributes to the damage of the environment. This study examines the adsorption biochar made from Annona reticulata to remove azo dye from textile wastewater. To improve the adsorption capacity, biochar valorized by chitosan molecules, Investigations were conducted on the use of chitosan-based materials that are acid-resistant for azo dye adsorption. In the batch experiment, basic operating parameters such as initial Azo dye concentrations, pH, contact time and bed height were assessed. The percentage removal efficiency for Azo dye was recorded as 67.18%, 75.88% and 94.37% for three dissimilar sized columns that were 6cm, 8cm, and 10cm. The UV–visible absorption spectroscopy was used to quantify the decolorization of dyes. The changed surface properties of the adsorbent produced from Annona reticulata were characterized by using SEM, XRD, and FTIR. The effectiveness of the column's adsorption was calculated mathematically by Yoon-Nelson, Thomas, and Adams-Bohart models. The model that best represents equilibrium isotherm data by adsorption had R2 values of 94.63, 86.67 and 96.35 respectively.</p>

show abstract

Nano-MnOx on activated carbon prepared by hydrothermal process for fast and highly efficient degradation of azo dyes

Cited by 36 publications

References 31 publications

Decolorization of RhB dye by manganese oxides: effect of crystal type and solution pH

Decolorization of RhB dye by manganese oxides: effect of crystal type and solution pH

A general nonaqueous sol-gel route to g-C3N4-coupling photocatalysts: the case of Z-scheme g-C3N4/TiO2 with enhanced photodegradation toward RhB under visible-light

Valorization of Annona reticulata biochar by chitosan for the adsorption of Azo dye from Textile effluent

Contact Info

Product

Resources

About