In this study, Pb(Ⅱ) was used as a target heavy metal pollutant, and the metabolism of Shewanella putrefaciens(S. putrefaciens) was applied to achieve reducing conditions to study the effect of microbial reduction on...In this study, Pb(Ⅱ) was used as a target heavy metal pollutant, and the metabolism of Shewanella putrefaciens(S. putrefaciens) was applied to achieve reducing conditions to study the effect of microbial reduction on lead that was preadsorbed on graphene oxide(GO) surfaces.The results showed that GO was transformed to its reduced form(r-GO) by bacteria, and this process induced the release of Pb(Ⅱ) adsorbed on the GO surfaces. After 72 hr of exposure in an S. putrefaciens system, 5.76% of the total adsorbed Pb(Ⅱ) was stably dispersed in solution in the form of a Pb(Ⅱ)-extracellular polymer substance(EPS) complex, while another portion of Pb(Ⅱ) released from GO-Pb(Ⅱ) was observed as lead phosphate hydroxide(Pb_(10)(PO_(4))_(6)(OH)_(2))precipitates or adsorbed species on the surface of the cell. Additionally, increasing pH induced the stripping of oxidative debris(OD) and elevated the content of dispersible Pb(Ⅱ)in aqueous solution under the conditions of S. putrefaciens metabolism. These research results provide valuable information regarding the migration of heavy metals adsorbed on GO under reducing conditions due to microbial metabolism.展开更多
A fundamental challenge in chemistry and materials science is to create new carbon nanomaterials by assembling structurally unique carbon building blocks,such as nonplanar π-conjugated cyclic molecules.However,self-a...A fundamental challenge in chemistry and materials science is to create new carbon nanomaterials by assembling structurally unique carbon building blocks,such as nonplanar π-conjugated cyclic molecules.However,self-assembly of such cyclic π-molecules to form organized nanostructures has been rarely explored despite intensive studies on their chemical synthesis.Here we synthesized a family of new cycloparaphenylenes and found that these fully hydrophobic and nonplanar cyclic π-molecules could self-assemble into structurally distinct two-dimensional crystalline multilayer nanosheets.Moreover,these crystalline multilayer nanosheets could overcome inherent rigidity to curve into closed crystalline vesicles in solution.Tese supramolecular assemblies show that the cyclic molecular scafolds are homogeneously arranged on the surface of nanosheets and vesicles with their molecular isotropic x-y plane standing obliquely on the surface.Tese supramolecular architectures that combined exact crystalline order,orientation-specifc arrangement of π-conjugated cycles,controllable morphology,uniform molecular pore,superior forescence quench ability,and photoluminescence are expected to give rise to a new class of functional materials displaying unique photonic,electronic,and biological functions.展开更多
There is a great demand for self-assembled carbon nanomaterials because of their importance in optoelectronics,biomaterials,and so forth.Herein,we report a novel type of self-assembled,nanoscale,crystalline vesicle fr...There is a great demand for self-assembled carbon nanomaterials because of their importance in optoelectronics,biomaterials,and so forth.Herein,we report a novel type of self-assembled,nanoscale,crystalline vesicle from nonplanarπ-conjugated nanocycles.We designed four different structural[8]cycloparaphenylenes([8]CPPs)molecules and demonstrated that these nonplanarπ-conjugated CPP nanocycles could self-assemble into multilamellar,crystalline vesicles in tetrahydrofuran(THF)/H2O mixed solvent.展开更多
基金This work was supported Foundation for Returned Education of China, Key by the Scientific Research Scholars, the Ministry of Basic Research Projects of Science and Technology Commission of Shanghai （No.11JC1412900）, and the National Science Foundation of China program （Nos. 21271140, 51472182）.
基金supported by the National Key Project of Research and Development Plan of China (No. 2017YFC04034033)the Shanxi National Science Foundation (No. 2020JQ-664)the Key Laboratory of Education Department of Shanxi Province, China (No. 20JS085)。
文摘In this study, Pb(Ⅱ) was used as a target heavy metal pollutant, and the metabolism of Shewanella putrefaciens(S. putrefaciens) was applied to achieve reducing conditions to study the effect of microbial reduction on lead that was preadsorbed on graphene oxide(GO) surfaces.The results showed that GO was transformed to its reduced form(r-GO) by bacteria, and this process induced the release of Pb(Ⅱ) adsorbed on the GO surfaces. After 72 hr of exposure in an S. putrefaciens system, 5.76% of the total adsorbed Pb(Ⅱ) was stably dispersed in solution in the form of a Pb(Ⅱ)-extracellular polymer substance(EPS) complex, while another portion of Pb(Ⅱ) released from GO-Pb(Ⅱ) was observed as lead phosphate hydroxide(Pb_(10)(PO_(4))_(6)(OH)_(2))precipitates or adsorbed species on the surface of the cell. Additionally, increasing pH induced the stripping of oxidative debris(OD) and elevated the content of dispersible Pb(Ⅱ)in aqueous solution under the conditions of S. putrefaciens metabolism. These research results provide valuable information regarding the migration of heavy metals adsorbed on GO under reducing conditions due to microbial metabolism.
基金This work was supported by National Key R&D Program of China(2017YFA0701301 and 2017YFA0205400)the Natural Science Foundation of China(Nos.51690153 and 21720102005)the Program for Changjiang Scholars and Innovative Research Team in University.We thank Prof.H.Li for his help in the XRD data analysis.
文摘A fundamental challenge in chemistry and materials science is to create new carbon nanomaterials by assembling structurally unique carbon building blocks,such as nonplanar π-conjugated cyclic molecules.However,self-assembly of such cyclic π-molecules to form organized nanostructures has been rarely explored despite intensive studies on their chemical synthesis.Here we synthesized a family of new cycloparaphenylenes and found that these fully hydrophobic and nonplanar cyclic π-molecules could self-assemble into structurally distinct two-dimensional crystalline multilayer nanosheets.Moreover,these crystalline multilayer nanosheets could overcome inherent rigidity to curve into closed crystalline vesicles in solution.Tese supramolecular assemblies show that the cyclic molecular scafolds are homogeneously arranged on the surface of nanosheets and vesicles with their molecular isotropic x-y plane standing obliquely on the surface.Tese supramolecular architectures that combined exact crystalline order,orientation-specifc arrangement of π-conjugated cycles,controllable morphology,uniform molecular pore,superior forescence quench ability,and photoluminescence are expected to give rise to a new class of functional materials displaying unique photonic,electronic,and biological functions.
基金supported by the Natural Science Foundation of China(nos.51690153 and 21720102005)the National Key R&D Program of China(nos.2017YFA0701301 and 2017YFA0205401)the Program for Changjiang Scholars and Innovative Research Team in University.
文摘There is a great demand for self-assembled carbon nanomaterials because of their importance in optoelectronics,biomaterials,and so forth.Herein,we report a novel type of self-assembled,nanoscale,crystalline vesicle from nonplanarπ-conjugated nanocycles.We designed four different structural[8]cycloparaphenylenes([8]CPPs)molecules and demonstrated that these nonplanarπ-conjugated CPP nanocycles could self-assemble into multilamellar,crystalline vesicles in tetrahydrofuran(THF)/H2O mixed solvent.
