Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane deve...Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane development.Here,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) nanosheets.The 3D flower-like nanostructures broaden the transport channels of the composite membrane.The membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic capabilities.The remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.展开更多
Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation memb...Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation membranes owing to its superiority.Here,we prepared a hyperbranched PEI-based separation mem-brane through the supramolecular hydrogen bond interaction for wastewater purification.The amino groups in the PEI molecule were partially oxidized to the nitro groups with sodium hypochlorite(NaClO).Moreover,the PEI molecu-lar chains can be regulated from the hyperbranched state to the internal nucle-ation state.Molecular dynamics simulation results further indicated the strong hydrogen bonds among the oxidized PEI(O-PEI)molecular chains and the decreased gyration radius of the O-PEI molecule due to the formation of the nitro groups.In addition,the wettability and zeta potential of O-PEI membranes can be controlled by adjusting the molecular weight and oxidation degree of the PEI molecules.Under the collective effect of size screening and charge repulsion,the O-PEI separation membrane displayed a wide range of purification capabilities for contaminations,such as dye molecules and salts.This work may offer a new strategy to fabricate hyperbranched O-PEI membranes for wastewater purifica-tion.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,CHD(Nos.300102312403 and 300102313208)the Shaanxi Key Research&Development Project(No.2022GY-403)+1 种基金the Innovation Capability Support Program of Shaanxi(No.2023-CX-TD-43)the China Postdoctoral Science Foundation(No.2020M683395).
文摘Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane development.Here,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) nanosheets.The 3D flower-like nanostructures broaden the transport channels of the composite membrane.The membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic capabilities.The remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.
基金This work was supported by the K.C.Wong Education Foundation(GJTD-2019-13)National Key Research and Develop-ment Program of China(2019YFC1606600)+1 种基金Shaanxi Key Research and Development Project(2020ZDLGY13-08),the Open Research Fund of Key Laboratory of Marine Materials and Related Technologies(2013DP173296,2019K03)Shaanxi Key Research and Development Project(2021GY199).
文摘Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation membranes owing to its superiority.Here,we prepared a hyperbranched PEI-based separation mem-brane through the supramolecular hydrogen bond interaction for wastewater purification.The amino groups in the PEI molecule were partially oxidized to the nitro groups with sodium hypochlorite(NaClO).Moreover,the PEI molecu-lar chains can be regulated from the hyperbranched state to the internal nucle-ation state.Molecular dynamics simulation results further indicated the strong hydrogen bonds among the oxidized PEI(O-PEI)molecular chains and the decreased gyration radius of the O-PEI molecule due to the formation of the nitro groups.In addition,the wettability and zeta potential of O-PEI membranes can be controlled by adjusting the molecular weight and oxidation degree of the PEI molecules.Under the collective effect of size screening and charge repulsion,the O-PEI separation membrane displayed a wide range of purification capabilities for contaminations,such as dye molecules and salts.This work may offer a new strategy to fabricate hyperbranched O-PEI membranes for wastewater purifica-tion.