The stronger coordination ability of mercury ions with organic ligands than the metal ions in metal organic framework(MOFs) provides an accessible way to separate mercury ions from solution using specific MOFs. In thi...The stronger coordination ability of mercury ions with organic ligands than the metal ions in metal organic framework(MOFs) provides an accessible way to separate mercury ions from solution using specific MOFs. In this study, a Co-based MOF(ZIF-67, Co(mIM)) was synthesized. It did not introduce specific functional groups, such as-SH and-NH, into its structure through complicated steps. It separate Hgfrom wastewater with a new strategy, which utilized the stronger coordination ability of Hgwith the nitrogen atom on the imidazole ring of the organic ligand than the Coions. Hgreplaced Conodes from ZIF-67 and formed a more stable precipitate with m IM. The experimental results showed that this new strategy was efficient. ZIF-67 exhibited Hgadsorption capacity of 1740 mg/g, much higher than the known MOFs sorbents. m IMs is the reaction center and ZIF-67 can improve its utilization. The sample color faded from purple to white due to the loss of cobalt ion. It is a great feature of ZIF-67 that allows users to judge whether the sorbent is deactivated intuitively. ZIF-67 can be sustainable recycled by adding organic ligands to the solution after treatment due to its simple synthesis method at room temperature. It’s a high-efficient and sustainable sorbent for Hgseparation from wastewater.展开更多
Mercury is the most toxic and harmful heavy metal pollutant, and it is essential to detect and remove mercury from beverages. Inducing the porphyrin molecules into the chitosan structure, a novel membrane sensor tetra...Mercury is the most toxic and harmful heavy metal pollutant, and it is essential to detect and remove mercury from beverages. Inducing the porphyrin molecules into the chitosan structure, a novel membrane sensor tetrakis(4-carboxyphenyl)porphyrin-grafted chitosan fiber membrane (TCPP-CS) was prepared by electrospinning method and applied to recognize Hg^(2+) contaminant selectively. Compared with other common metal ions (Pb^(2+), Cu^(2+), Fe^(3+), Cr^(3+), Mg^(2+), and Zn^(2+)), the colorimetric sensor has specific color development and sensitivity to Hg^(2+) and the detection limit of the sensor reaches 1 × 10^(−5) mol·L^(−1). The response time of the membrane is 5 s, and it can be specifically colored in various pH environments convenient for practical application. Hg^(2+) resulted in a visual color change of the fiber membrane from brown to yellow-green, indicating a potential interaction between the porphyrin-functionalized chitosan fiber membrane and Hg^(2+) ions, and the wavelength shift of the UV–visible spectrum can be observed. It has the advantages of simplicity, rapidity, high selectivity, and high sensitivity, providing a new method for removing and detecting heavy metals in traditional Chinese medicine and drinks.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51778229 , 21307032 )the Fundamental Research Funds for the Central Universities (No. JKB012015019 )。
文摘The stronger coordination ability of mercury ions with organic ligands than the metal ions in metal organic framework(MOFs) provides an accessible way to separate mercury ions from solution using specific MOFs. In this study, a Co-based MOF(ZIF-67, Co(mIM)) was synthesized. It did not introduce specific functional groups, such as-SH and-NH, into its structure through complicated steps. It separate Hgfrom wastewater with a new strategy, which utilized the stronger coordination ability of Hgwith the nitrogen atom on the imidazole ring of the organic ligand than the Coions. Hgreplaced Conodes from ZIF-67 and formed a more stable precipitate with m IM. The experimental results showed that this new strategy was efficient. ZIF-67 exhibited Hgadsorption capacity of 1740 mg/g, much higher than the known MOFs sorbents. m IMs is the reaction center and ZIF-67 can improve its utilization. The sample color faded from purple to white due to the loss of cobalt ion. It is a great feature of ZIF-67 that allows users to judge whether the sorbent is deactivated intuitively. ZIF-67 can be sustainable recycled by adding organic ligands to the solution after treatment due to its simple synthesis method at room temperature. It’s a high-efficient and sustainable sorbent for Hgseparation from wastewater.
基金supported by Natural Science Foundation-Steel and Iron Foundation of Hebei Province of China(No.B2020209022)PhD Startup Program of North China University of Science and Technology(No.BS2017031)Tianjin Science and Technology plan project(No.24ZYCGSN01250).
文摘Mercury is the most toxic and harmful heavy metal pollutant, and it is essential to detect and remove mercury from beverages. Inducing the porphyrin molecules into the chitosan structure, a novel membrane sensor tetrakis(4-carboxyphenyl)porphyrin-grafted chitosan fiber membrane (TCPP-CS) was prepared by electrospinning method and applied to recognize Hg^(2+) contaminant selectively. Compared with other common metal ions (Pb^(2+), Cu^(2+), Fe^(3+), Cr^(3+), Mg^(2+), and Zn^(2+)), the colorimetric sensor has specific color development and sensitivity to Hg^(2+) and the detection limit of the sensor reaches 1 × 10^(−5) mol·L^(−1). The response time of the membrane is 5 s, and it can be specifically colored in various pH environments convenient for practical application. Hg^(2+) resulted in a visual color change of the fiber membrane from brown to yellow-green, indicating a potential interaction between the porphyrin-functionalized chitosan fiber membrane and Hg^(2+) ions, and the wavelength shift of the UV–visible spectrum can be observed. It has the advantages of simplicity, rapidity, high selectivity, and high sensitivity, providing a new method for removing and detecting heavy metals in traditional Chinese medicine and drinks.
