In this work,we present a top-down method for the preparation of 2D MOF nanosheets with cavity structures.The pro-ligand 25,26,27,28-tetrakis[(carboxyl)methoxy]calix[4]arene was elaborately selected,and a layered MOF ...In this work,we present a top-down method for the preparation of 2D MOF nanosheets with cavity structures.The pro-ligand 25,26,27,28-tetrakis[(carboxyl)methoxy]calix[4]arene was elaborately selected,and a layered MOF with cavity structures was constructed.The large molecular skeleton and cup-shaped feature of the calix[4]arene caused large layer separations and weak interlayer interactions among the 2D layers,which enabled the layered MOF to be readily delaminated into ultrathin 2D MOF nanosheets.Owing to the cup-shaped feature of the calix[4]arene,there are permanent cage-like cavities loaded on the as-prepared MOF nanosheets.By decorating oxygen-containing functional groups(carboxyl and ether groups)in the cage-like cavities,the resultant Cu-MOF nanosheets showed excellent adsorption performance for Pb^(2+).The intimate contact and sufficient interactions on the exposed surface areas of Cu-MOF nanosheet resulted in ultrahigh adsorption selectivity and anti-interference ability for Pb^(2+),together with an outstanding Pb^(2+)uptake capacity of 738.65 mg g^(-1),which were obviously better than those of its 3D precursor.The possible adsorption mechanism was systematically investigated by the investigations of zeta potential,FT-IR,XPS,and DFT calculations.This study opens the door to achieving ultrathin MOF nanosheets with cavity structures,which would well expand the applications of MOF nanosheets.展开更多
Layered oxychalcogenides namely the SmCrS_(2−x)Se_(x)O(x=0–2)solid solutions,were synthesized via high-temperature solid-state reactions.SmCrQ_(2)O(Q=S,Se)crystallizes in the monoclinic space group of C2/m(No.12),fea...Layered oxychalcogenides namely the SmCrS_(2−x)Se_(x)O(x=0–2)solid solutions,were synthesized via high-temperature solid-state reactions.SmCrQ_(2)O(Q=S,Se)crystallizes in the monoclinic space group of C2/m(No.12),featuring typical layered structures.The two-dimensional(2D)_(∞)^(2)[CrQ_(2)O]^(3−)motifs stack along the a axis,which are separated by Sm^(3+)ions.The_(∞)^(2)[CrQ_(2)O]^(3−)layers are composed of[CrQ_(6)]^(9−)and[CrQ_(4)O_(2)]^(9−)octahedra via corner and edge sharing.The in-plane Cr atoms feature a distorted honeycomb arrangement with prolonged Cr⋯Cr distances along the c axis.The powder X-ray diffraction results confirm the phase purities and the formation of solid solutions.Magnetic measurements indicate that the SmCrS_(2−x)Se_(x)O solid solutions show typical antiferromagnetic ordering.The Néer temperatures(TN)increase from 74 K to 121 K with the decrease in S content.展开更多
The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study p...The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study proposes an innovative process that harnesses the overcuring of resins in digital light processing(DLP)3D printing to emulate setae structures.The proposed method facilitates the spontaneous fabrication of anisotropic shapes from isotropically modeled geometries.Furthermore,it reduces the number of hierarchical structures typically produced in conventional 3D printing and creates smooth surfaces,thereby enhancing the structural stability for directional adhesion and detachment.The anisotropic structures were processed into functional surfaces through a double-casting method,exhibiting an adhesive strength akin to that of gecko-setae structures while maintaining easy detachment capabilities.Finally,a simple mechanical module was fabricated to directly demonstrate the detachment effect.This study introduces a novel approach to DLP printing for fabricating enhanced anisotropic structures that can be seamlessly integrated with existing 3D printing techniques.By strategically utilizing overcuring,a phenomenon often perceived as a limitation,this study demonstrated its potential to expand the boundaries of next-generation 3D printing technologies.展开更多
基金supported by the Natural Science Foundation of Shandong Province(ZR2021MB106 and ZR2021QB090)the Major Projects of Natural Science Research in Universities of Jiangsu Province(20KJA150002)the Huaishang Talent Program of Huaian.
文摘In this work,we present a top-down method for the preparation of 2D MOF nanosheets with cavity structures.The pro-ligand 25,26,27,28-tetrakis[(carboxyl)methoxy]calix[4]arene was elaborately selected,and a layered MOF with cavity structures was constructed.The large molecular skeleton and cup-shaped feature of the calix[4]arene caused large layer separations and weak interlayer interactions among the 2D layers,which enabled the layered MOF to be readily delaminated into ultrathin 2D MOF nanosheets.Owing to the cup-shaped feature of the calix[4]arene,there are permanent cage-like cavities loaded on the as-prepared MOF nanosheets.By decorating oxygen-containing functional groups(carboxyl and ether groups)in the cage-like cavities,the resultant Cu-MOF nanosheets showed excellent adsorption performance for Pb^(2+).The intimate contact and sufficient interactions on the exposed surface areas of Cu-MOF nanosheet resulted in ultrahigh adsorption selectivity and anti-interference ability for Pb^(2+),together with an outstanding Pb^(2+)uptake capacity of 738.65 mg g^(-1),which were obviously better than those of its 3D precursor.The possible adsorption mechanism was systematically investigated by the investigations of zeta potential,FT-IR,XPS,and DFT calculations.This study opens the door to achieving ultrathin MOF nanosheets with cavity structures,which would well expand the applications of MOF nanosheets.
基金supported by the Innovation Program of the CAS(Grant KJCX2-EW-W11)the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grants XDB04040200)+3 种基金the NSF of China(Grants 91122034,51125006,51202279,61376056,and 21201012)the Science and Technology Commission of Shanghai(Grant 12XD1406800)the Research Grant of Qian Xuesen Laboratory of Space Technology(Y-KC-WY-99-ZY-000-013)the Qian Xuesen Youth Innovation Fund(Y-KC-JT-QXS-012).
文摘Layered oxychalcogenides namely the SmCrS_(2−x)Se_(x)O(x=0–2)solid solutions,were synthesized via high-temperature solid-state reactions.SmCrQ_(2)O(Q=S,Se)crystallizes in the monoclinic space group of C2/m(No.12),featuring typical layered structures.The two-dimensional(2D)_(∞)^(2)[CrQ_(2)O]^(3−)motifs stack along the a axis,which are separated by Sm^(3+)ions.The_(∞)^(2)[CrQ_(2)O]^(3−)layers are composed of[CrQ_(6)]^(9−)and[CrQ_(4)O_(2)]^(9−)octahedra via corner and edge sharing.The in-plane Cr atoms feature a distorted honeycomb arrangement with prolonged Cr⋯Cr distances along the c axis.The powder X-ray diffraction results confirm the phase purities and the formation of solid solutions.Magnetic measurements indicate that the SmCrS_(2−x)Se_(x)O solid solutions show typical antiferromagnetic ordering.The Néer temperatures(TN)increase from 74 K to 121 K with the decrease in S content.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2023-00260527).
文摘The anisotropic setae structures of geckos demonstrate a natural anisotropic response to external forces,thereby enabling rapid and repeated attachment and detachment.Considering this biological mechanism,this study proposes an innovative process that harnesses the overcuring of resins in digital light processing(DLP)3D printing to emulate setae structures.The proposed method facilitates the spontaneous fabrication of anisotropic shapes from isotropically modeled geometries.Furthermore,it reduces the number of hierarchical structures typically produced in conventional 3D printing and creates smooth surfaces,thereby enhancing the structural stability for directional adhesion and detachment.The anisotropic structures were processed into functional surfaces through a double-casting method,exhibiting an adhesive strength akin to that of gecko-setae structures while maintaining easy detachment capabilities.Finally,a simple mechanical module was fabricated to directly demonstrate the detachment effect.This study introduces a novel approach to DLP printing for fabricating enhanced anisotropic structures that can be seamlessly integrated with existing 3D printing techniques.By strategically utilizing overcuring,a phenomenon often perceived as a limitation,this study demonstrated its potential to expand the boundaries of next-generation 3D printing technologies.
