This letter focuses on the synthesis of multi-walled carbon nanotubes(MWNTs) and MWNTs/ZnO nanocomposites using absorbent cotton.The MWNTs have been synthesized by a rapid heating of absorbent cotton at different temp...This letter focuses on the synthesis of multi-walled carbon nanotubes(MWNTs) and MWNTs/ZnO nanocomposites using absorbent cotton.The MWNTs have been synthesized by a rapid heating of absorbent cotton at different temperature(400,550,600).The MWNTs/ZnO nanocomposites have been synthesized by heating mixtures of Zn(OH)_2/H_2O/absorbent cotton at different temperature(at about 550 and600).The X-ray diffraction(XRD) pattern and energy dispersive spectrum(EDS) clearly show that the pure MWNTs and ZnO nanocomposites(with a mean size of 35.9 nm) were synthesized.The scanning electron microscopy(SEM) images demonstrate that the structure of synthesized MWNTs was middle-hollow,with inner and outer diameter of around 10 and 80 nm.The ZnO nanocomposites that had grown on the walls of MWNTs were nonuniform and agglomerated,with an outer diameter of around 110 nm.The selected area diffraction(SAD) patterns and Raman spectrum indicate that the MWNTs were well-crystallised,and there are a few defects in the walls.Infrared absorption spectroscopy(IR) spectra suggest that the surface of MWNTs has been covered by ZnO.展开更多
In this paper, we have demonstrated a facile and low-cost synthesis of the ZnO/CuO nanocomposites by two-step hydrothermal methods. The photocatalytic properties of the as-synthesized ZnO/CuO nanocomposites have been ...In this paper, we have demonstrated a facile and low-cost synthesis of the ZnO/CuO nanocomposites by two-step hydrothermal methods. The photocatalytic properties of the as-synthesized ZnO/CuO nanocomposites have been evaluated by the photodegradation of methylene blue(MB) and methyleneorange(MO) under UV irradiation. Experimental results show that MB and MO can be degraded completely within 15 and 25 min by the ZnO/CuO nanocomposites and its photodegradation rate is 6 times faster than that of pure ZnO. This enhanced photocatalytic activity can be ascribed to the low recombination probability of photo-induced carriers due to the efficient charge transfer in the nanocomposites. The as-synthesized ZnO/CuO nanocomposite may be a promising candidate for dye photodegradation of wastewaters.展开更多
In order to achieve effective, economic, and easily achievable photocatalyst for the degradation of dye methyl orange(MeO), ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanocomposites were prepared by simple chemical synthetic...In order to achieve effective, economic, and easily achievable photocatalyst for the degradation of dye methyl orange(MeO), ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanocomposites were prepared by simple chemical synthetic route in the aqueous medium. Phase, crystallinity, surface structure and surface behavior of the synthesized materials were determined by X-ray diffraction(XRD) and Brunauer-Emmett-Teller analysis(BET) techniques. XRD study established formation of good crystalline ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanomaterials. By using intensity of constituent peaks in the XRD pattern, the compositions of nanocomposites were determined. From the BET analysis, the prepared materials show mesoporous behavior, type Ⅳ curves along with H4 hysteresis. The ZnO/ZnS/α-Fe2O3 composite shows the largest surface area among three materials. From the UV-visible spectra, the band gap energy of the materials was determined. Photoluminescence spectra(PL) were used to determine the emission behavior and surface defects in the materials. In PL spectra, the intensity of UV peak of ZnO/ZnS is lowered than that of ZnO while in case of ZnO/ZnS/α-Fe2O3, the intensity further decreased. The visible emission spectra of ZnO/ZnS increased compared with ZnO while in ZnO/ZnS/α-Fe2O3 it is further increased compared with ZnO/ZnS. The as-synthesized materials were used as photocatalysts for the degradation of dye MeO. The photo-degradation data revealed that the ZnO/ZnS/α-Fe2O3 is the best photocatalyst among three specimens for the degradation of dye MeO. The decrease of intensity of UV emission peak and the increase of intensity of visible emission cause the decrease of recombination of electrons and holes which are ultimately responsible for the highest photocatalytic activity of ZnO/ZnS/α-Fe2O3.展开更多
Nanocomposites of zinc/bentonite clay were synthesized for use as an antibacterial material by a quick and simple alkaline ion exchange method. The synthesis of zinc doped bentonite nanocomposite was accomplished by p...Nanocomposites of zinc/bentonite clay were synthesized for use as an antibacterial material by a quick and simple alkaline ion exchange method. The synthesis of zinc doped bentonite nanocomposite was accomplished by placing bentonite in a melting bath of ZnSO4 for 10, 20, 40, 60 and 90 rain. The complexes were characterized by XRD, SEM and DRS. XRD analyses and SEM observations confirmed the diffusion of zinc to the clay surfaces. Antibacterial activity tests against Escherichia coli showed that bentonite did not present any antibacterial properties, but after alkaline ion exchange treatment, inhibition was noted. The highest antibacterial activity was observed with ZnO/bentonite composite alkaline ion exchange for 60 and 90 rain. Interestingly, the leaching test indicated that ZnO/bentonite did not present any risk for drinking water treatment.展开更多
In this research study, we have synthesized the bio-capped ZnO/g-C_(3)N_(4) nanocomposites by employing lemon juice(Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic fun...In this research study, we have synthesized the bio-capped ZnO/g-C_(3)N_(4) nanocomposites by employing lemon juice(Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic functional groups and citric acid has the capability to block the surface of g-C_(3)N_(4) from chemical reactivity and activated the surface of g-C_(3)N_(4) for various reactions. Consequently, the agglomeration behavior and controlled shape of g-C_(3)N_(4) has also been achieved. Our experimental results i.e. XRD,TEM, HRTEM, PL, FS, XPS, and PEC have confirmed that the lemon juice mediated and green g-C_(3)N_(4)(L-CN) have good performances and remarkable visible light photocatalytic activities as compared to the chemically synthesized g-C_(3)N_(4)(CN). Furthermore, the small surface area and low charge separation of g-C_(3)N_(4) is upgraded by coupling with Zn O nanoparticles. It is proved that the coupling of Zn O worked as a facilitator and photoelectron modulator to enhance the charge separation of g-C_(3)N_(4). Compared to pristine lemon-mediated green g-C_(3)N_(4)(L-CN), the most active sample 5Zn O/L-CN showed ~ 5-fold improvement in activities for ciprofloxacin(CIP) and methylene blue(MB) degradation. More specifically,the mineralization process and degradation pathways, and the mineralization process of ciprofloxacin(CIP) and methylene blue(MB) are suggested. Finally, our present novel research work will provide new access to synthesize the eco-friendly and bio-caped green g-C_(3)N_(4)nanomaterials and their employment for pollutants degradation and environmental purification.展开更多
Zinc oxide/low-density polyethylene (LDPE) nanocomposites were prepared for intrauterine devices. The change of Zn^2+ release rates of nanocomposites ( doped with various mass fractions of zinc oxide nanoparticles...Zinc oxide/low-density polyethylene (LDPE) nanocomposites were prepared for intrauterine devices. The change of Zn^2+ release rates of nanocomposites ( doped with various mass fractions of zinc oxide nanoparticles between 5wt% and 65 wt% ) for 264 days in a simulated uterine solution were investigated. The resuits show that initial burst phases are followed by near zero-order release phases. SEM technique was employed to observe the surface morphology of the 45wt% ZnO/ LDPE composite. Elements and phases on the surface of the nanocomposite after incubation were also analyzed by EDX and XRD respectively. The experimental results show that incrustation formation does not occur after incubation.展开更多
ZnO quantum dots (QDs) as an eco-friendly and low-cost material has bright fluorescence, which makes it promising material for healthy lighting and displaying. However, the low fluorescence efficiency and poor stabi...ZnO quantum dots (QDs) as an eco-friendly and low-cost material has bright fluorescence, which makes it promising material for healthy lighting and displaying. However, the low fluorescence efficiency and poor stability of ZnO QDs impede their applications in lighting application. In this work, silica encapsulated ZnO QD-phosphors nanocomposites (ZSPN) have been prepared through a sol-gel synthesis process, where yellow-emitting ZnO QDs and blue-emitting BaMgAl10O17:Eu2+ are employed as the luminescence cores and silica as link between two luminescence materials. Tunable photoluminescence of ZSPN and the white light emission have been achieved through changing mass ratio of both of ZnO QDs and commercial phosphors. The PLQY of the ZSPN can reach 63.7% and they can maintain high luminous in- tensity even the ambient temperature up to 110 ℃ and after 35 h of UV irradiation. In addition, they can keep stable for 40 days. By coating the ZSPN phosphors onto a ultraviolet chip, WLEDs with luminous efficiency of 73.6 lm/W and the color coordinate, correlated color temperature, and color rendering index can reach (0.32, 0.34), 5580 K, and 87, respectively, indicating the bright prospect of the ZSPN phosphors used in healthy lighting.展开更多
Graphene-ZnO nanocomposites were synthesized successfully through a one-step solvothermal approach. The mor-phology, structure, and composition of the prepared nanocomposites were investigated by scanning electron mic...Graphene-ZnO nanocomposites were synthesized successfully through a one-step solvothermal approach. The mor-phology, structure, and composition of the prepared nanocomposites were investigated by scanning electron microscopy (SEM), transmission electron microscope (TEM), laser micro Raman spectroscopy, and Fourier transform infra-red spec-troscopy (FT-IR). The outcomes confirmed that this approach is comparatively steady, practicable, and operable compared with other reported methods. The electrochemical performance of the graphene-ZnO electrodes was analyzed through cyclic voltammetry, altering-current (AC) impedance, and chronopotentiometry tests. The graphene-ZnO electrodes exhib-ited an improved electrode performance with higher specific capacitance (115 F·g^-1 ), higher electrochemical stability, and higher energy density than the graphene electrodes and most reported graphene-ZnO electrodes. Graphene-ZnO nanocom-posites have a steady reversible charge/discharge behavior, which makes them promising candidates for electrochemical capacitors (ECs).展开更多
TiO_(2)-ZnO nanocomposites were synthesized by varying Ti:Zn molar ratio from 1:0.1(TZ-1:0.1)to 1:1(TZ-1:1).With increase in Zn content,from TZ-1:0.1 to TZ-1:0.2,anatase transformed to rutile phase.TZ-1:0.3,which cont...TiO_(2)-ZnO nanocomposites were synthesized by varying Ti:Zn molar ratio from 1:0.1(TZ-1:0.1)to 1:1(TZ-1:1).With increase in Zn content,from TZ-1:0.1 to TZ-1:0.2,anatase transformed to rutile phase.TZ-1:0.3,which contained a blend of phases,including rutile and anatase TiO_(2),ZnO,and zinc titanates,exhibited the narrowest bandgap(2.5±0.1 e V),and showed the highest photocatalytic activity.TZ-1:1 was predominated by zinc titanates.All the nanocomposites exhibited narrower bandgaps compared to pure TiO_(2)nanoparticles,facilitating visible light activity.This study was designed to explore whether a method targeting the removal of a specific crystalline phase(anatase)influenced the properties and photocatalytic activity of the nanocomposite.Selective dissolution not only removed anatase phase,but also led to significant loss of crystallinity,widened the bandgap,and adversely affected photocatalytic performance,in nanocomposites that contained>80%anatase phase(TZ-1:0.1 and TZ-1:0.2).However,in nanocomposites that contained less of anatase phase(TZ-1:0.3and TZ-1:1),the morphology,bandgap,crystallinity,and the extent of photocatalytic activity at the end of 240 min remained largely unaffected.Photocatalytic activity in TZ-1:0.3 and TZ-1:1 originated from a blend of phases comprising of less photocatalytically active phases,such as rutile TiO_(2),Zn TiO3,and Zn2TiO4,rather than from the anatase phase.The Ti:Zn molar ratio controlled the phases present in TiO_(2)-ZnO nanocomposites,which,in turn,controlled the physicochemical properties and visible light activity.Thus,in nanocomposites that contained a mix of several phases,the properties and photocatalytic activity were not dependent on anatase phase.展开更多
In this investigation, polymeric nanocomposite membranes(PNMs) were prepared via incorporating zinc oxide(ZnO) into poly(ether-block-amide)(PEBAX-1074) polymer matrix with different loadings. The neat membrane a...In this investigation, polymeric nanocomposite membranes(PNMs) were prepared via incorporating zinc oxide(ZnO) into poly(ether-block-amide)(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy(FESEM) to survey cross-sectional morphologies and thermal gravimetric analysis(TGA)to study thermal stability. Fourier transform infrared(FT-IR) and X-ray diffraction(XRD) analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.展开更多
A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities an...A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities and coulomb efficiencies of Snl MWNTs were studied by means of electrochemical methods. The coating of Sn on MWNTs observed by TEM was amorphous and nano-sized. The reversible capacity of Sn/ MWNTs , which was much larger than that of MWNTs , was 824 mAh/ g in the 1 st charge and discharge cycle. The coulomb efficiency of Sn/ MWNTs in the 1 st cycle was increased by 16% compared with that of MWNTs. The additional Sn, which was 37wt% of total Sn/ MWNTs' weight, introduced the additional reversible lithiation capacity at least 250 mAh/ g in the 40 charge and discharge cycles. The dispersing degree of Sn on MWNTs was the main reason for the influence of the electrochemical perfomance of the Sn/ MWNTs . Sn/ MWNTs is proved to be a promising candidate as an anode of lithium ion battery.展开更多
Polysulfonamide/zinc oxide(PSA/ZnO) nanocomposite films with w(ZnO)=0.5% were prepared by in-situ polymerization based on 4,4′-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N,N-Dimethylaceta...Polysulfonamide/zinc oxide(PSA/ZnO) nanocomposite films with w(ZnO)=0.5% were prepared by in-situ polymerization based on 4,4′-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N,N-Dimethylacetamide(DMAc). Atomic force microscopy (AFM) was employed to observe the microstructure of the composite film. The thermal property was investigated by TGA and mechanical property was characterized by DXLL-1000 electromechanical material testing machine. The results showed that the breaking strength of the film containing 0.5% ZnO was great enhanced. The average size of ZnO particles was below 100 nm. The introduction of ZnO as nano filler in PSA react as UV shield effect and make the composite mechanical property improved.展开更多
In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different...In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different optical and structural techniques.The XRD study revealed the existence of a wurtzite structure with no extra oxide peaks.Elemental-mapping,EDX,FTIR and XPS analyses were used to confirm the presence of elements and the several groups present in the structure.Under excitations of UV,the prepared hybrid nanocomposite showed a strong cyan emission with narrow full width at half the maximum value(20 nm)that has not been reported before.X-ray and laser-induced luminescence results of the hy-brid film revealed novel blue-green emission at room temperature.The prepared composite film showed a strong scintillation re-sponse to ionizing radiation.The strong emissions,very weak deep-level emissions,and low FWHM of composite indicate the de-sirable optical properties with low-density structural defects in the GZO composite structure.Therefore,the prepared hybrid film can be considered to be a suitable candidate for the fabrication of optoelectronic devices.展开更多
The nanocomposites of ZnO-SnO_2 and In_2O_3-SnO_2 were prepared by wet chemical co-precipitation method as a novel semiconductor gas sensing materials for the detection of environmentally toxic gases.Controlled prepar...The nanocomposites of ZnO-SnO_2 and In_2O_3-SnO_2 were prepared by wet chemical co-precipitation method as a novel semiconductor gas sensing materials for the detection of environmentally toxic gases.Controlled preparation parameters were critical towards the grain size and crystallinity of the obtained nanocomposites.The results showed that these nanocomposites exhibited high sensitivity and selectivity for the detection of CO and NO_x,and the sensitivity depended on the composition of the composite,calcination temperature and operating temperature.The gas sensing properties of the sensors were further improved through incorporation of dopants and surface additives.The gas sensing mechanism was also discussed by X-ray photoelectron spectroscopic (XPS) and temperature-programmed desorption (TPD) studies.展开更多
A new type of inorganic-polymer materials of epoxy Titanium Dioxide and Zinc Oxide was prepared. In this work, the mechanical properties of polymer composites reinforced with ceramic nanoparticles were investigated. T...A new type of inorganic-polymer materials of epoxy Titanium Dioxide and Zinc Oxide was prepared. In this work, the mechanical properties of polymer composites reinforced with ceramic nanoparticles were investigated. Three points bending tests demonstrated an enhancement in flexural strength and flexural modulus respectively, compared to the pure epoxy. The reinforcement of nanoparticulate materials was Titanium Dioxide and Zinc Oxide with various weight fraction. Experimental tests results indicated that the composite materials have significantly higher modulus of elasticity than the matrix material. It was found that the enhancement in modulus of elasticity was directly proportional to the weight fraction of reinforcement material, and that Zinc Oxide composites have higher modulus of elasticity than Titanium Dioxide composites with equivalent of weight fraction. The wear results showed that nanoparticles improved the wear resistance of epoxy nanocomposites, the Titanium Dioxide matrix particles could improve the wear resistance of the epoxy more efficiently than Zinc Oxide particles. The fatigue test showed that the fatigue resistance of epoxy Zinc Oxide matrix particles was higher than that of Titanium Dioxide matrix particles.展开更多
基金partly supported by the National Natural Science Foundation of China (21003081)the Liaoning Education Department Projects (2010010,2006032)
文摘This letter focuses on the synthesis of multi-walled carbon nanotubes(MWNTs) and MWNTs/ZnO nanocomposites using absorbent cotton.The MWNTs have been synthesized by a rapid heating of absorbent cotton at different temperature(400,550,600).The MWNTs/ZnO nanocomposites have been synthesized by heating mixtures of Zn(OH)_2/H_2O/absorbent cotton at different temperature(at about 550 and600).The X-ray diffraction(XRD) pattern and energy dispersive spectrum(EDS) clearly show that the pure MWNTs and ZnO nanocomposites(with a mean size of 35.9 nm) were synthesized.The scanning electron microscopy(SEM) images demonstrate that the structure of synthesized MWNTs was middle-hollow,with inner and outer diameter of around 10 and 80 nm.The ZnO nanocomposites that had grown on the walls of MWNTs were nonuniform and agglomerated,with an outer diameter of around 110 nm.The selected area diffraction(SAD) patterns and Raman spectrum indicate that the MWNTs were well-crystallised,and there are a few defects in the walls.Infrared absorption spectroscopy(IR) spectra suggest that the surface of MWNTs has been covered by ZnO.
基金support from the National Natural Science and Henan Province United Foundation of China (No. U1204601)Natural Science Foundation of Henan Province (No. 122300410298)+1 种基金Natural Science Foundation of Education Department of Henan Province (No. 13A480365)PhD Foundation of Zhengzhou University of Light Industry (No. 2010BSJJ029)
文摘In this paper, we have demonstrated a facile and low-cost synthesis of the ZnO/CuO nanocomposites by two-step hydrothermal methods. The photocatalytic properties of the as-synthesized ZnO/CuO nanocomposites have been evaluated by the photodegradation of methylene blue(MB) and methyleneorange(MO) under UV irradiation. Experimental results show that MB and MO can be degraded completely within 15 and 25 min by the ZnO/CuO nanocomposites and its photodegradation rate is 6 times faster than that of pure ZnO. This enhanced photocatalytic activity can be ascribed to the low recombination probability of photo-induced carriers due to the efficient charge transfer in the nanocomposites. The as-synthesized ZnO/CuO nanocomposite may be a promising candidate for dye photodegradation of wastewaters.
文摘In order to achieve effective, economic, and easily achievable photocatalyst for the degradation of dye methyl orange(MeO), ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanocomposites were prepared by simple chemical synthetic route in the aqueous medium. Phase, crystallinity, surface structure and surface behavior of the synthesized materials were determined by X-ray diffraction(XRD) and Brunauer-Emmett-Teller analysis(BET) techniques. XRD study established formation of good crystalline ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanomaterials. By using intensity of constituent peaks in the XRD pattern, the compositions of nanocomposites were determined. From the BET analysis, the prepared materials show mesoporous behavior, type Ⅳ curves along with H4 hysteresis. The ZnO/ZnS/α-Fe2O3 composite shows the largest surface area among three materials. From the UV-visible spectra, the band gap energy of the materials was determined. Photoluminescence spectra(PL) were used to determine the emission behavior and surface defects in the materials. In PL spectra, the intensity of UV peak of ZnO/ZnS is lowered than that of ZnO while in case of ZnO/ZnS/α-Fe2O3, the intensity further decreased. The visible emission spectra of ZnO/ZnS increased compared with ZnO while in ZnO/ZnS/α-Fe2O3 it is further increased compared with ZnO/ZnS. The as-synthesized materials were used as photocatalysts for the degradation of dye MeO. The photo-degradation data revealed that the ZnO/ZnS/α-Fe2O3 is the best photocatalyst among three specimens for the degradation of dye MeO. The decrease of intensity of UV emission peak and the increase of intensity of visible emission cause the decrease of recombination of electrons and holes which are ultimately responsible for the highest photocatalytic activity of ZnO/ZnS/α-Fe2O3.
文摘Nanocomposites of zinc/bentonite clay were synthesized for use as an antibacterial material by a quick and simple alkaline ion exchange method. The synthesis of zinc doped bentonite nanocomposite was accomplished by placing bentonite in a melting bath of ZnSO4 for 10, 20, 40, 60 and 90 rain. The complexes were characterized by XRD, SEM and DRS. XRD analyses and SEM observations confirmed the diffusion of zinc to the clay surfaces. Antibacterial activity tests against Escherichia coli showed that bentonite did not present any antibacterial properties, but after alkaline ion exchange treatment, inhibition was noted. The highest antibacterial activity was observed with ZnO/bentonite composite alkaline ion exchange for 60 and 90 rain. Interestingly, the leaching test indicated that ZnO/bentonite did not present any risk for drinking water treatment.
基金Jiangsu University of Science and Technology for providing financial support under the Research start-up fund for the introduction of young talent at Jiangsu University of Science and Technology (Grant no. 1112932205)High-level Talents Program of Shihezi University (RCZK2021B25)。
文摘In this research study, we have synthesized the bio-capped ZnO/g-C_(3)N_(4) nanocomposites by employing lemon juice(Citrus limon) as a stabilizer and mediator. Fruitfully, lemon juice which contains various acidic functional groups and citric acid has the capability to block the surface of g-C_(3)N_(4) from chemical reactivity and activated the surface of g-C_(3)N_(4) for various reactions. Consequently, the agglomeration behavior and controlled shape of g-C_(3)N_(4) has also been achieved. Our experimental results i.e. XRD,TEM, HRTEM, PL, FS, XPS, and PEC have confirmed that the lemon juice mediated and green g-C_(3)N_(4)(L-CN) have good performances and remarkable visible light photocatalytic activities as compared to the chemically synthesized g-C_(3)N_(4)(CN). Furthermore, the small surface area and low charge separation of g-C_(3)N_(4) is upgraded by coupling with Zn O nanoparticles. It is proved that the coupling of Zn O worked as a facilitator and photoelectron modulator to enhance the charge separation of g-C_(3)N_(4). Compared to pristine lemon-mediated green g-C_(3)N_(4)(L-CN), the most active sample 5Zn O/L-CN showed ~ 5-fold improvement in activities for ciprofloxacin(CIP) and methylene blue(MB) degradation. More specifically,the mineralization process and degradation pathways, and the mineralization process of ciprofloxacin(CIP) and methylene blue(MB) are suggested. Finally, our present novel research work will provide new access to synthesize the eco-friendly and bio-caped green g-C_(3)N_(4)nanomaterials and their employment for pollutants degradation and environmental purification.
文摘Zinc oxide/low-density polyethylene (LDPE) nanocomposites were prepared for intrauterine devices. The change of Zn^2+ release rates of nanocomposites ( doped with various mass fractions of zinc oxide nanoparticles between 5wt% and 65 wt% ) for 264 days in a simulated uterine solution were investigated. The resuits show that initial burst phases are followed by near zero-order release phases. SEM technique was employed to observe the surface morphology of the 45wt% ZnO/ LDPE composite. Elements and phases on the surface of the nanocomposite after incubation were also analyzed by EDX and XRD respectively. The experimental results show that incrustation formation does not occur after incubation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21601159,61604132,and U1604263)the National Science Fund for Distinguished Young Scholars of China(Grant No.61425021)
文摘ZnO quantum dots (QDs) as an eco-friendly and low-cost material has bright fluorescence, which makes it promising material for healthy lighting and displaying. However, the low fluorescence efficiency and poor stability of ZnO QDs impede their applications in lighting application. In this work, silica encapsulated ZnO QD-phosphors nanocomposites (ZSPN) have been prepared through a sol-gel synthesis process, where yellow-emitting ZnO QDs and blue-emitting BaMgAl10O17:Eu2+ are employed as the luminescence cores and silica as link between two luminescence materials. Tunable photoluminescence of ZSPN and the white light emission have been achieved through changing mass ratio of both of ZnO QDs and commercial phosphors. The PLQY of the ZSPN can reach 63.7% and they can maintain high luminous in- tensity even the ambient temperature up to 110 ℃ and after 35 h of UV irradiation. In addition, they can keep stable for 40 days. By coating the ZSPN phosphors onto a ultraviolet chip, WLEDs with luminous efficiency of 73.6 lm/W and the color coordinate, correlated color temperature, and color rendering index can reach (0.32, 0.34), 5580 K, and 87, respectively, indicating the bright prospect of the ZSPN phosphors used in healthy lighting.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61265004,51272097,and 11204113)the Nature and Science Fund from Yunnan Province Ministry of Education,China(Grant No.2011C13211708)the Natural Training Project from University of Shanghai for Science and Technology,China(Grant No.14XPM06)
文摘Graphene-ZnO nanocomposites were synthesized successfully through a one-step solvothermal approach. The mor-phology, structure, and composition of the prepared nanocomposites were investigated by scanning electron microscopy (SEM), transmission electron microscope (TEM), laser micro Raman spectroscopy, and Fourier transform infra-red spec-troscopy (FT-IR). The outcomes confirmed that this approach is comparatively steady, practicable, and operable compared with other reported methods. The electrochemical performance of the graphene-ZnO electrodes was analyzed through cyclic voltammetry, altering-current (AC) impedance, and chronopotentiometry tests. The graphene-ZnO electrodes exhib-ited an improved electrode performance with higher specific capacitance (115 F·g^-1 ), higher electrochemical stability, and higher energy density than the graphene electrodes and most reported graphene-ZnO electrodes. Graphene-ZnO nanocom-posites have a steady reversible charge/discharge behavior, which makes them promising candidates for electrochemical capacitors (ECs).
基金provided by Department of Science and Technology,New Delhi,India,under the Water Technology Initiative(WTI)scheme(Project code:DST/TM/WTI/2K15/101(G)).
文摘TiO_(2)-ZnO nanocomposites were synthesized by varying Ti:Zn molar ratio from 1:0.1(TZ-1:0.1)to 1:1(TZ-1:1).With increase in Zn content,from TZ-1:0.1 to TZ-1:0.2,anatase transformed to rutile phase.TZ-1:0.3,which contained a blend of phases,including rutile and anatase TiO_(2),ZnO,and zinc titanates,exhibited the narrowest bandgap(2.5±0.1 e V),and showed the highest photocatalytic activity.TZ-1:1 was predominated by zinc titanates.All the nanocomposites exhibited narrower bandgaps compared to pure TiO_(2)nanoparticles,facilitating visible light activity.This study was designed to explore whether a method targeting the removal of a specific crystalline phase(anatase)influenced the properties and photocatalytic activity of the nanocomposite.Selective dissolution not only removed anatase phase,but also led to significant loss of crystallinity,widened the bandgap,and adversely affected photocatalytic performance,in nanocomposites that contained>80%anatase phase(TZ-1:0.1 and TZ-1:0.2).However,in nanocomposites that contained less of anatase phase(TZ-1:0.3and TZ-1:1),the morphology,bandgap,crystallinity,and the extent of photocatalytic activity at the end of 240 min remained largely unaffected.Photocatalytic activity in TZ-1:0.3 and TZ-1:1 originated from a blend of phases comprising of less photocatalytically active phases,such as rutile TiO_(2),Zn TiO3,and Zn2TiO4,rather than from the anatase phase.The Ti:Zn molar ratio controlled the phases present in TiO_(2)-ZnO nanocomposites,which,in turn,controlled the physicochemical properties and visible light activity.Thus,in nanocomposites that contained a mix of several phases,the properties and photocatalytic activity were not dependent on anatase phase.
文摘In this investigation, polymeric nanocomposite membranes(PNMs) were prepared via incorporating zinc oxide(ZnO) into poly(ether-block-amide)(PEBAX-1074) polymer matrix with different loadings. The neat membrane and nanocomposite membranes were prepared via solution casting and solution blending methods, respectively. The fabricated membranes were characterized by field emission scanning electron microscopy(FESEM) to survey cross-sectional morphologies and thermal gravimetric analysis(TGA)to study thermal stability. Fourier transform infrared(FT-IR) and X-ray diffraction(XRD) analyses were also employed to identify variations of the chemical bonds and crystal structure of the membranes, respectively. Permeation of pure gases, CO, CHand Nthrough the prepared neat and nanocomposite membranes was studied at pressures of 3–18 bar and temperature of 25 °C. The obtained results showed that the fabricated nanocomposite membranes exhibit better separation performance compared to the neat PEBAX membrane in terms of both permeability and selectivity. As an example, at temperature of 25 °C and pressure of 3 bar, COpermeability, ideal CO/CHand CO/Nselectivity values for the neat PEBAX membrane are 110.67 Barrer, 11.09 and 50.08, respectively, while those values are 152.27 Barrer,13.52 and 62.15 for PEBAX/ZnO nanocomposite membrane containing 8 wt% ZnO.
基金Funded by the National Basic Research Programof China( No.2003CB61570)
文摘A chemical deposition was supposed to be an effwient method in preparation of nano-sized Sn/ MWNTs. The nanoconmposites of MWNTs and Sn/ MWNTs were both used as anodes of lithium ion battery. The special capacities and coulomb efficiencies of Snl MWNTs were studied by means of electrochemical methods. The coating of Sn on MWNTs observed by TEM was amorphous and nano-sized. The reversible capacity of Sn/ MWNTs , which was much larger than that of MWNTs , was 824 mAh/ g in the 1 st charge and discharge cycle. The coulomb efficiency of Sn/ MWNTs in the 1 st cycle was increased by 16% compared with that of MWNTs. The additional Sn, which was 37wt% of total Sn/ MWNTs' weight, introduced the additional reversible lithiation capacity at least 250 mAh/ g in the 40 charge and discharge cycles. The dispersing degree of Sn on MWNTs was the main reason for the influence of the electrochemical perfomance of the Sn/ MWNTs . Sn/ MWNTs is proved to be a promising candidate as an anode of lithium ion battery.
基金Education Commission of Shanghai (No04AB19)Science and Technology Commission of Shanghai Municipal Government(Nano Founds No 0452NM051)
文摘Polysulfonamide/zinc oxide(PSA/ZnO) nanocomposite films with w(ZnO)=0.5% were prepared by in-situ polymerization based on 4,4′-diaminodiphenylsulfone and terephthaloyl chloride in the common solvent N,N-Dimethylacetamide(DMAc). Atomic force microscopy (AFM) was employed to observe the microstructure of the composite film. The thermal property was investigated by TGA and mechanical property was characterized by DXLL-1000 electromechanical material testing machine. The results showed that the breaking strength of the film containing 0.5% ZnO was great enhanced. The average size of ZnO particles was below 100 nm. The introduction of ZnO as nano filler in PSA react as UV shield effect and make the composite mechanical property improved.
基金the Iranian National Elites Foundation for the financial support of this research
文摘In the present study,a simple method for the preparation of a luminescent flexible gallium doped zinc oxide(GZO)/polystyrene nanocomposite film was developed.The prepared GZO powder was characterized through different optical and structural techniques.The XRD study revealed the existence of a wurtzite structure with no extra oxide peaks.Elemental-mapping,EDX,FTIR and XPS analyses were used to confirm the presence of elements and the several groups present in the structure.Under excitations of UV,the prepared hybrid nanocomposite showed a strong cyan emission with narrow full width at half the maximum value(20 nm)that has not been reported before.X-ray and laser-induced luminescence results of the hy-brid film revealed novel blue-green emission at room temperature.The prepared composite film showed a strong scintillation re-sponse to ionizing radiation.The strong emissions,very weak deep-level emissions,and low FWHM of composite indicate the de-sirable optical properties with low-density structural defects in the GZO composite structure.Therefore,the prepared hybrid film can be considered to be a suitable candidate for the fabrication of optoelectronic devices.
基金This research was supported by the National Natural Science Foundation of China (No. 20577001);Beijing Natural Science Foundation (No. 8042016 and 8062011).
文摘The nanocomposites of ZnO-SnO_2 and In_2O_3-SnO_2 were prepared by wet chemical co-precipitation method as a novel semiconductor gas sensing materials for the detection of environmentally toxic gases.Controlled preparation parameters were critical towards the grain size and crystallinity of the obtained nanocomposites.The results showed that these nanocomposites exhibited high sensitivity and selectivity for the detection of CO and NO_x,and the sensitivity depended on the composition of the composite,calcination temperature and operating temperature.The gas sensing properties of the sensors were further improved through incorporation of dopants and surface additives.The gas sensing mechanism was also discussed by X-ray photoelectron spectroscopic (XPS) and temperature-programmed desorption (TPD) studies.
文摘A new type of inorganic-polymer materials of epoxy Titanium Dioxide and Zinc Oxide was prepared. In this work, the mechanical properties of polymer composites reinforced with ceramic nanoparticles were investigated. Three points bending tests demonstrated an enhancement in flexural strength and flexural modulus respectively, compared to the pure epoxy. The reinforcement of nanoparticulate materials was Titanium Dioxide and Zinc Oxide with various weight fraction. Experimental tests results indicated that the composite materials have significantly higher modulus of elasticity than the matrix material. It was found that the enhancement in modulus of elasticity was directly proportional to the weight fraction of reinforcement material, and that Zinc Oxide composites have higher modulus of elasticity than Titanium Dioxide composites with equivalent of weight fraction. The wear results showed that nanoparticles improved the wear resistance of epoxy nanocomposites, the Titanium Dioxide matrix particles could improve the wear resistance of the epoxy more efficiently than Zinc Oxide particles. The fatigue test showed that the fatigue resistance of epoxy Zinc Oxide matrix particles was higher than that of Titanium Dioxide matrix particles.