Publications by authors named "Zhangjie Qin"

3 Publications

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The Controlled Synthesis of Birnessite Nanoflowers HO Reducing KMnO For Efficient Adsorption and Photooxidation Activity.

Front Chem 2021 26;9:699513. Epub 2021 May 26.

Key Laboratory of Poyang Lake Watershed Agricultural Resources and Ecology of Jiangxi Province, College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang, China.

Birnessite nanoflowers composed of layers have been proven to be the strongest adsorbent and oxidant in the surface environment. However, the current synthesis methods of birnessite nanoflowers are suffering from long reaction time and high reaction temperature. Based on these, this paper explores a new method for the rapid and controlled synthesis of layered manganese oxides. The method relies on the molar ratios of KMnO and HO redox reacting species to drive the production of birnessite nanoflowers under acidic conditions. The molar ratios of KMnO and HO are the key to the crystal structure of the as-prepared. It was found that when the molar ratios of KMnO and HO is from 1:1.25 to 1:1.90, the sample is birnessite nanoflowers, and when the ratio is increased to 1:2.0, the sample is a mixture of birnessite nanoflowers and feitknechtite nanoplates. Among the as-prepared samples, BF-1.85 (molar ratios of KMnO and HO is 1:1.85) shows the highest capacity for Pb adsorption (2,955 mmol/kg) and greatest degradation efficiency of phenol and TOC. The method proposed herein is economical and controllable, and it yields products with high efficiency for the elimination of inorganic and organic pollutants.
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http://dx.doi.org/10.3389/fchem.2021.699513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8187863PMC
May 2021

Kinetics of Mn(II) adsorption and catalytic oxidation on the surface of ferrihydrite.

Sci Total Environ 2021 Jun 4;791:148225. Epub 2021 Jun 4.

Key Laboratory of Poyang Lake Basin Agricultural Resource and Ecology of Jiangxi Province, College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang 330045, China. Electronic address:

Mn(II) adsorption-oxidation on iron (Fe) oxides (e.g., ferrihydrite) occurs in various soils and sediments, significantly affecting the toxicities and bioavailabilities of Mn and other associated elements. However, the detailed processes of Mn(II) adsorption-oxidation on ferrihydrite remain elusive. In this study, the Mn(II) (2 mM) adsorption-oxidation kinetics on different masses of ferrihydrite (0.25, 0.50, 1.00, and 1.25 g) at pH 7 were determined using batch kinetic studies combined with X-ray diffraction, transmission electron microscopy, and wet chemistry analyses. The results indicated that the low-concentration Mn(II) adsorption-oxidation on ferrihydrite occurred in two steps. First, Mn(II) was adsorbed onto ferrihydrite, where it was partially oxidized by the catalytic effect of ferrihydrite, within ~0-60 min; subsequently, the remaining Mn(II) underwent autocatalytic oxidation on the previously generated Mn (oxyhydr)oxides. The initial adsorption-oxidation behaviors of Mn(II) on the ferrihydrite surface determined the kinetics of Mn(II) removal and oxidation, and therefore the amounts and types of Mn (oxyhydr)oxides formed. Furthermore, the specific characteristics of Mn(II) adsorption-oxidation on ferrihydrite showed a strong dependence on the Fe/Mn molar ratio. When this ratio was below 16.35, the initial process was dominated by Mn(II) adsorption onto ferrihydrite, with slight oxidation generating hausmannite (~0-60 min), followed by the catalytic oxidation of Mn(II) on the formed hausmannite, generating manganite or groutite. Conversely, when the Fe/Mn molar ratio was above 32.7, the reactions primarily involved Mn(II) adsorption onto ferrihydrite with minor oxidation to form Mn(III/IV) (oxyhydr)oxides (~0-60 min), followed by the autocatalytic oxidation of Mn(II) on the freshly-generated Mn(III/IV) (oxyhydr)oxides, forming Mn(III) (oxyhydr)oxides, i.e., feitknechtite. These results provide further insight into the interaction between Fe and Mn, Mn(II) removal, and Mn (oxyhydr)oxide formation in the environment.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148225DOI Listing
June 2021

Coordination geometry of Zn on hexagonal turbostratic birnessites with different Mn average oxidation states and its stability under acid dissolution.

J Environ Sci (China) 2018 Mar 7;65:282-292. Epub 2017 Mar 7.

Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River) Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China. Electronic address:

Hexagonal turbostratic birnessite, with the characteristics of high contents of vacancies, varying amounts of structural and adsorbed Mn, and small particle size, undergoes strong adsorption reactions with trace metal (TM) contaminants. While the interactions of TM, i.e., Zn, with birnessite are well understood, the effect of birnessite structural characteristics on the coordination and stability of Zn on the mineral surfaces under proton attack is as yet unclear. In the present study, the effects of a series of synthesized hexagonal turbostratic birnessites with different Mn average oxide states (AOSs) on the coordination geometry of adsorbed Zn and its stability under acidic conditions were investigated. With decreasing Mn AOS, birnessite exhibits smaller particle sizes and thus larger specific surface area, higher amounts of layer Mn and thus longer distances for the first MnO and MnMn shells, but a low quantity of available vacancies and thus low adsorption capacity for Zn. Zn K-edge EXAFS spectroscopy demonstrates that birnessite with low Mn AOS has smaller adsorption capacity but more tetrahedral Zn (Zn) complexes on vacancies than octahedral (Zn) complexes, and Zn is more unstable under acidic conditions than that adsorbed on birnessite with high Mn AOS. High Zn loading favors the formation of Zn complexes over Zn complexes, and the release of Zn is faster than at low loading. These results will deepen our understanding of the interaction mechanisms of various TMs with natural birnessites, and the stability and thus the potential toxicity of heavy metal pollutants sequestered by engineered nano-sized metal oxide materials.
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http://dx.doi.org/10.1016/j.jes.2017.02.017DOI Listing
March 2018
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