Publications (9)11.97 Total impact
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Article: Enhanced photocatalytic degradation of methylene blue on multiwalled carbon nanotubes-TiO2.
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ABSTRACT: A visible-light photocatalyst of multiwalled carbon nanotubes decorated with TiO2 nanoparticles (MWCNT/TiO2) was synthesized by a two-step method, in which TiO2 was first mounted on MWCNT surfaces by hydrolysis of tetrabutyl titanate and further crystallized into anatase nanocrystal in a vacuum furnace at 500°C. The photocatalytic degradation of methylene blue over the ultraviolet (UV) and visible-light spectrum regions was investigated. The MWCNT/TiO2 was able to absorb a high amount of photo energy in the visible-light region, driving effectively photochemical degradation reactions. There were more OH radicals produced by the MWCNT/TiO2 (1:3) than by pure TiO2 under UV and visible-light irradiation. In the photodegradation of methylene blue, as a model reaction, a signification enhancement in the reaction rate was observed with the MWCNT/TiO2 (1:3), compared to bare TiO2 and the physical mixture of MWCNTs and TiO2. MWCNTs can improve the photocatalytic activity of TiO2 in two aspects, namely e(-) transportation and adsorption. This work provides new insight into the fabrication of MWCNT/TiO2 as a high performance visible-light photocatalyst and facilitates its application in photocatalytic degradation of organic compounds.Journal of Colloid and Interface Science 02/2013; · 3.07 Impact Factor -
Article: Impact of water quality parameters on the sorption of U(VI) onto hematite.
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ABSTRACT: In this study, the sorption of U(VI) from aqueous solution on hematite was studied as a function of various water quality parameters such as contact time, pH, ionic strength, soil humic acid (HA) or fulvic acid (FA), solid content and temperature by using a batch technique. The results demonstrated that the sorption of U(VI) was strongly dependent on ionic strength at pH<6.0, and outer-sphere surface complexation may be the main sorption mechanism. The sorption was independent of ionic strength at pH>6.0 and the sorption was mainly dominated by inner-sphere surface complexation. The presence of HA/FA increases U(VI) sorption at low pH, whereas decreases U(VI) sorption at high pH. The thermodynamic parameters (ΔH⁰, ΔS⁰, and ΔG⁰) were calculated from the temperature dependent sorption isotherms, and the results suggested that U(VI) sorption was a spontaneous and endothermic process. The results might be important for the application of hematite in U(VI) pollution management.Journal of environmental radioactivity 01/2012; 103(1):20-9. · 1.47 Impact Factor -
Article: Effect of environmental conditions on the retention behaviour of Pb(II) by hematite
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ABSTRACT: BACKGROUND: The retention behaviour of Pb(II) by hematite was studied as a function of various environmental parameters such as contact time, pH, ionic strength, foreign ions, humic substances and temperature under ambient conditions.RESULTS: Pb(II) sorption on hematite was rapid and the sorption could be described by a pseudo-second-order model very well. The sorption of Pb(II) on hematite was strongly dependent on pH and ionic strength. The presence of humic substances enhanced the sorption of Pb(II) on hematite at low pH, but reduced Pb(II) sorption at high pH. The Langmuir model fitted the sorption isotherms of Pb(II) better than the Freundlich model at three different temperatures, 293.15, 313.15 and 333.15 K. The thermodynamic parameters (ΔH°,ΔS° and ΔG°) calculated from the temperature dependent sorption isotherms indicated that the sorption process of Pb(II) on hematite was endothermic and spontaneous.CONCLUSIONS: The results indicate that hematite is a promising candidate for the treatment of heavy metal ions from large volume solution. Copyright © 2011 Society of Chemical IndustryJournal of Chemical Technology & Biotechnology 04/2011; 86(8):1099 - 1106. · 2.17 Impact Factor -
Article: Influence of solution chemistry on the removal of Ni (II) from aqueous solution to titanate nanotubes
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ABSTRACT: a b s t r a c t In this work, adsorption of Ni(II) from aqueous solution to titanate nanotubes (TNTs) as a function of various water quality parameters was investigated under ambient conditions. The results indicated that the adsorption of Ni(II) to TNTs was strongly dependent on pH and ionic strength. A positive effect of humic acid (HA)/fulvic acid (FA) on Ni(II) adsorption was found at pH < 6.0, whereas a negative effect was observed at pH > 6.0. At low pH, the adsorption of Ni(II) was dominated by outer-sphere surface complexation or ion exchange with Na + /H + on TNT surfaces, whereas inner-sphere surface complexation was the main adsorption mechanism at high pH. The TNTs are suitable material for the preconcentration of Ni(II) from large volumes of aqueous solutions.Chemical Engineering Journal. 01/2011; 168:178-182. -
Article: Removal of Pb(II) and Cu(II) from aqueous solution using multiwalled carbon nanotubes/iron oxide magnetic composites.
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ABSTRACT: Multiwalled carbon nanotubes (MWCNTs)/iron oxide magnetic composites (named as MCs) were prepared by co-precipitation method, and were characterised by scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) in detail. The prepared MCs were employed as an adsorbent for the removal of Pb(II) and Cu(II) ions from wastewater in heavy metal ion pollution cleanup. The results demonstrated that the sorption of Pb(II) and Cu(II) ions was strongly dependent on pH and temperature. The experimental data were well described by Langmuir model, and the monolayer sorption capacity of MCs was found to vary from 10.02 to 31.25 mg/g for Pb(II) and from 3.11 to 8.92 mg/g for Cu(II) at temperature increasing from 293.15 to 353.15 K at pH 5.50. The sorption capacity of Pb(II) on MCs was higher than that of Cu(II), which was attributed to their ionic radius, hydration energies and hydrolysis of their hydroxides. The thermodynamic parameters (i.e., ΔH(0), ΔS(0) and ΔG(0)) were calculated from temperature dependent sorption isotherms, and the results indicated that the sorption of Pb(II) and Cu(II) ions on MCs were spontaneous and endothermic processes.Water Science & Technology 01/2011; 63(5):917-23. · 1.12 Impact Factor -
Article: Impact of environmental conditions on the sorption behavior of Pb(II) in Na-bentonite suspensions.
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ABSTRACT: In this study, a local bentonite from Lin'an county (Zhejiang province, China) was converted to Na-purified form and the Na-bentonite sample was characterized by using FTIR and XRD to determine its chemical constituents and micro-structure. The removal of lead from wastewaters by Na-bentonite was studied as a function of various environmental parameters such as contact time, pH, ionic strength, foreign ions, humic substances and temperature under ambient conditions. The results indicated that the sorption of Pb(II) on Na-bentonite was strongly dependent on pH and ionic strength. The Langmuir, Freundlich and D-R models were used to simulate the sorption isotherms of Pb(II) at three different temperatures of 298, 318 and 338 K. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) calculated from the temperature dependent sorption isotherms indicated that the sorption process of Pb(II) on Na-bentonite was endothermic and spontaneous. At low pH, the sorption of Pb(II) was dominated by outer-sphere surface complexation and ion exchange with Na(+)/H(+) on Na-bentonite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. From the experimental results, it is possible to conclude that Na-bentonite has good potentialities for cost-effective disposal of lead bearing wastewaters.Journal of hazardous materials 11/2010; 183(1-3):632-40. · 4.14 Impact Factor -
Article: Effect of environmental conditions on Pb(II) adsorption on β-MnO2
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ABSTRACT: In this study, the adsorption of Pb(II) on β-MnO2 as a function of various environmental conditions such as contact time, pH, ionic strength, humic acid (HA)/fulvic acid (FA), and temperature was investigated using batch techniques. The results indicated that the adsorption of Pb(II) on β-MnO2 was obviously dependent on pH but independent of ionic strength. The presence of HA/FA enhanced the adsorption of Pb(II) on β-MnO2 at low pH, whereas reduced Pb(II) adsorption on β-MnO2 at high pH. The kinetic adsorption of Pb(II) on β-MnO2 can be well fitted by the pseudo-second-order rate equation. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) were also calculated from the temperature dependent adsorption isotherms, and the results suggested that the adsorption of Pb(II) on β-MnO2 was a spontaneous and endothermic process. The adsorption of Pb(II) on β-MnO2 was attributed to surface complexation rather than ion exchange.Chemical Engineering Journal. -
Article: The adsorption of Pb(II) on Mg2Al layered double hydroxide
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ABSTRACT: The adsorption behavior of Pb(II) by Mg2Al layered double hydroxide (Mg2Al LDH) was studied as a function of contact time, pH, ionic strength, foreign ions, humic substances and temperature under ambient conditions. The results showed that the kinetic adsorption could be described by a pseudo-second order model very well. The adsorption of Pb(II) on Mg2Al LDH was strongly dependent on pH and ionic strength. The presence of HSs enhanced the adsorption of Pb(II) on Mg2Al LDH at low pH, whereas reduced Pb(II) adsorption at high pH. The Langmuir model fitted the adsorption isotherms of Pb(II) better than the Freundlich model at three different temperatures of 303.15, 323.15 and 343.15 K. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) calculated from the temperature dependent adsorption isotherms indicated that the adsorption process of Pb(II) on Mg2Al LDH was endothermic and spontaneous. The results show that Mg2Al LDH is a promising material for the preconcentration and separation of pollutants from large volumes of aqueous solutions.Highlights► Pb(II) adsorption on Mg2Al LDH was dependent on pH and ionic strength. ► HSs enhanced Pb(II) adsorption on Mg2Al LDH at low pH, whereas reduced Pb(II) adsorption at high pH. ► The Langmuir model fitted the adsorption isotherms of Pb(II) well. ► Pb(II) adsorption on Mg2Al LDH was endothermic and spontaneous.Chemical Engineering Journal. 171(1):167-174. -
Article: Adsorption kinetic, thermodynamic and desorption studies of Th(IV) on oxidized multi-wall carbon nanotubes
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ABSTRACT: The adsorption kinetics of Th(IV) on oxidized multi-wall carbon nanotubes (MWCNTs) was investigated at initial Th(IV) concentrations 32.32 and 64.64 μmol/L. The kinetic process was described by a pseudo-second-order rate model very well. The adsorption thermodynamics of Th(IV) on oxidized MWCNTs was carried out at 293 ± 2, 303 ± 2, and 323 ± 2 K, respectively, and the thermodynamic parameters, such as equilibrium constant (K0), standard free energy changes (ΔG°), standard enthalpy change (ΔH°) and standard entropy change (ΔS°), were obtained. The Langmuir model described the data better than the Freundlich isotherm model. Desorption studies indicated that Th(IV) adsorption was reversible and Th(IV) ions could be desorbed from the surface of carbon nanotubes by adjusting the pH values. Oxidized MWCNTs may be a promising candidate for the preconcentration and solidification of Th(IV), or its analogue actinides from large volumes.Colloids and Surfaces A: Physicochemical and Engineering Aspects.
Top co-authors
Top Journals
Institutions
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2011–2013
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Anhui University of Architecture
Hefei, Anhui Sheng, China -
North China Electric Power University
Beijing, Beijing Shi, China -
Chinese Academy of Sciences
- Institute of Plasma Physics (HF)
Beijing, Beijing Shi, China
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