Nano-sized zinc oxide(n ZnO) particles are one kind of the most commonly used metal oxide nanoparticles(NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles(φ30 nm, ...Nano-sized zinc oxide(n ZnO) particles are one kind of the most commonly used metal oxide nanoparticles(NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles(φ30 nm, 80-150 nm and 2 μm) in the flounder gill(FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn^(2+) to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size-and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn^(2+) ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size-and concentration-dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.展开更多
The widespread production and use of zinc oxide nanoparticles （ZnO-NPs） in recent years have posed potential threat to the ecosystem. This study aimed to investigate the ecotoxicological effect of ZnO-NPs on soil mi...The widespread production and use of zinc oxide nanoparticles （ZnO-NPs） in recent years have posed potential threat to the ecosystem. This study aimed to investigate the ecotoxicological effect of ZnO-NPs on soil microorganisms using laboratory microcosm test. Respira- tion, ammonification, dehydrogenase （DH） activity, and fluorescent diacetate hydrolase （FDAH） activity were used as ecotoxicological parameters. The results showed that in the neutral soil treated with 1 mg ZnO-NPs per g soil （fresh, neutral）, ammonification was significantly inhibited during the study period of three months, but the inhibition rate decreased over increasing time. Inhibition in respira- tion was observed in the first month of the test. In various ZnO-NPs treatments （1 rag, 5 rag, and 10 mg ZnO-NPs per g soil）, DH activity and FDAH activity were inhibited during the study period of one month. For both enzyme activities, there were positive dose-response relationships between the concentration of ZnO-NPs and the inhibition rates, but the curves changed over time due to changes of ZnO-NPs toxicity. Soil type affected the toxicity of ZnO- NPs in soil. The toxicity was highest in the acid soil, followed by the neutral soil. The toxicity was relatively low in the alkaline soil. The toxicity was not accounted for by the Zn2＋ released from the ZnO-NPs. Direct interaction of ZnO-NPs with biologic targets might be one of the reasons. The adverse effect of ZnO-NPs on soil micro- organisms in neutral and acid soils is worthy of attention.展开更多
ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced aceton...ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders.A combination of H_(2)O_(2)treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles(NPs).The highest response of~27,562 was achieved for 10 ppm acetone in 0.125 MH_(2)O_(2)treated/annealed ZnO NPs at the optimal working temperature of 400℃,which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors(MOSs).Furthermore,first-principles calculations indicate that pre-adsorbed O formed on the surface of H_(2)O_(2)treated ZnO NPs can provide favorable adsorption energy,especially for acetone detection,due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface.Our study demonstrates that controlling surface oxygen vacancies by H_(2)O_(2)treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.展开更多
In recent years, energy-retrofitting is becoming an imperative aim for existing buildings worldwide and increased interest has focused on the development of nanoparticle blended concretes with adequate mechanical...In recent years, energy-retrofitting is becoming an imperative aim for existing buildings worldwide and increased interest has focused on the development of nanoparticle blended concretes with adequate mechanical properties and durability performance, through the optimization of concrete permeability and the incorporation of the proper nanoparticle type in the concrete matrix. In order to investigate the potential use of nanocomposites as dense barriers against the permeation of liquids into the concrete, three types of nanoparticles including Zinc Oxide (ZnO), Magnesium Oxide (MgO), and composite nanoparticles were used in the present study as partial replacement of cement. Besides, the effect of adding these nanoparticles on both pore structure and mechanical strengths of the concrete at different ages was determined, and scanning electron microscopy (SEM) images were then used to illustrate the uniformity dispersion of nanoparticles in cement paste. It was demonstrated that the addition of a small number of nanoparticles effectively enhances the mechanical properties of concrete and consequently reduces the extent of the water permeation front. Finally, the behavioral models using Genetic Algorithm (GA) programming were developed to describe the time-dependent behavioral characteristics of nanoparticle blended concrete samples in various compressive and tensile stress states at different ages.展开更多
A photocatalyst of Au/ZnO(s-Au/ZnO)has been prepared via an approach,which uses spinach leaves with in terconnected hierarchical structure as sacrificial biological template.The resultant s-Au/ZnO has well maintained ...A photocatalyst of Au/ZnO(s-Au/ZnO)has been prepared via an approach,which uses spinach leaves with in terconnected hierarchical structure as sacrificial biological template.The resultant s-Au/ZnO has well maintained the physical characteristics of the spinach leaf and demonstrated superior photocatalytic performance as well as enhanced photocurrent generation capability.Moreover,functional sacrificial agents(AgNO3,ammonium oxalate(AO)and tert-butyl alcohol(TBA))have been employed to quench electrons,holes and hydroxyl radicals respectively to identify the active species of photocatalytic reaction and to investigate the mechanism of photocatalytic degradation.The facile method herein presented provides a convenient option for the preparation ofbio-inspired leaMike photocatalysts of ZnO-based nano-materials,holding potential applications in not only environmental purification but also solar-to-electric energy conversion.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41076075,31472274 and 31172391)Scholarship Foundation for Excellent Scientists of Shandong Province(Grant No.BS2011 SW054)open foundation from Institute of Marine Biodiversity and Evolution(Grant No.20132017)
文摘Nano-sized zinc oxide(n ZnO) particles are one kind of the most commonly used metal oxide nanoparticles(NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles(φ30 nm, 80-150 nm and 2 μm) in the flounder gill(FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn^(2+) to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size-and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn^(2+) ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size-and concentration-dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 41071311, 41030529 and 41471391）, Program for New Century Excellent Talents in University of Ministry of Education of China （NCET-10-0200） and YKM Entrepreneurship Education Foundation.
文摘The widespread production and use of zinc oxide nanoparticles （ZnO-NPs） in recent years have posed potential threat to the ecosystem. This study aimed to investigate the ecotoxicological effect of ZnO-NPs on soil microorganisms using laboratory microcosm test. Respira- tion, ammonification, dehydrogenase （DH） activity, and fluorescent diacetate hydrolase （FDAH） activity were used as ecotoxicological parameters. The results showed that in the neutral soil treated with 1 mg ZnO-NPs per g soil （fresh, neutral）, ammonification was significantly inhibited during the study period of three months, but the inhibition rate decreased over increasing time. Inhibition in respira- tion was observed in the first month of the test. In various ZnO-NPs treatments （1 rag, 5 rag, and 10 mg ZnO-NPs per g soil）, DH activity and FDAH activity were inhibited during the study period of one month. For both enzyme activities, there were positive dose-response relationships between the concentration of ZnO-NPs and the inhibition rates, but the curves changed over time due to changes of ZnO-NPs toxicity. Soil type affected the toxicity of ZnO- NPs in soil. The toxicity was highest in the acid soil, followed by the neutral soil. The toxicity was relatively low in the alkaline soil. The toxicity was not accounted for by the Zn2＋ released from the ZnO-NPs. Direct interaction of ZnO-NPs with biologic targets might be one of the reasons. The adverse effect of ZnO-NPs on soil micro- organisms in neutral and acid soils is worthy of attention.
基金supported by the Technology Innovation Program(No.20013621,Center for Super Critical Material Industrial Technology)funded by the Ministry of Trade,Industry&Energy(MOTIE,Republic of Korea)the Priority Research Centers Program(2019R1A6A1A11055660)+2 种基金the Basic Science Research Program(2017 M3A9F1052297)through the National Research Foundation of Korea(NRF),funded by the Republic of Korean Government(Ministry of Science and ICT)the support from the International Energy Joint R&D Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP),granted financial resource from the Ministry of Trade,Industry&Energy,Republic of Korea(20208510010310)the support from the Basic Research in Science and Engineering Program of the NRF(2021R1A2C1013690)。
文摘ZnO has been studied intensely for chemical sensors due to its high sensitivity and fast response.Here,we present a simple approach to precisely control oxygen vacancy contents to provide significantly enhanced acetone sensing performance of commercial ZnO nanopowders.A combination of H_(2)O_(2)treatment and thermal annealing produces optimal surface defects with oxygen vacancies on the ZnO nanoparticles(NPs).The highest response of~27,562 was achieved for 10 ppm acetone in 0.125 MH_(2)O_(2)treated/annealed ZnO NPs at the optimal working temperature of 400℃,which is significantly higher than that of reported so far in various acetone sensors based on metal oxide semiconductors(MOSs).Furthermore,first-principles calculations indicate that pre-adsorbed O formed on the surface of H_(2)O_(2)treated ZnO NPs can provide favorable adsorption energy,especially for acetone detection,due to strong bidentate bonding between carbonyl C atom of acetone molecules and pre-adsorbed O on the ZnO surface.Our study demonstrates that controlling surface oxygen vacancies by H_(2)O_(2)treatment and re-annealing at optimal temperature is an effective method to improve the sensing properties of commercial MOS materials.
文摘In recent years, energy-retrofitting is becoming an imperative aim for existing buildings worldwide and increased interest has focused on the development of nanoparticle blended concretes with adequate mechanical properties and durability performance, through the optimization of concrete permeability and the incorporation of the proper nanoparticle type in the concrete matrix. In order to investigate the potential use of nanocomposites as dense barriers against the permeation of liquids into the concrete, three types of nanoparticles including Zinc Oxide (ZnO), Magnesium Oxide (MgO), and composite nanoparticles were used in the present study as partial replacement of cement. Besides, the effect of adding these nanoparticles on both pore structure and mechanical strengths of the concrete at different ages was determined, and scanning electron microscopy (SEM) images were then used to illustrate the uniformity dispersion of nanoparticles in cement paste. It was demonstrated that the addition of a small number of nanoparticles effectively enhances the mechanical properties of concrete and consequently reduces the extent of the water permeation front. Finally, the behavioral models using Genetic Algorithm (GA) programming were developed to describe the time-dependent behavioral characteristics of nanoparticle blended concrete samples in various compressive and tensile stress states at different ages.
文摘A photocatalyst of Au/ZnO(s-Au/ZnO)has been prepared via an approach,which uses spinach leaves with in terconnected hierarchical structure as sacrificial biological template.The resultant s-Au/ZnO has well maintained the physical characteristics of the spinach leaf and demonstrated superior photocatalytic performance as well as enhanced photocurrent generation capability.Moreover,functional sacrificial agents(AgNO3,ammonium oxalate(AO)and tert-butyl alcohol(TBA))have been employed to quench electrons,holes and hydroxyl radicals respectively to identify the active species of photocatalytic reaction and to investigate the mechanism of photocatalytic degradation.The facile method herein presented provides a convenient option for the preparation ofbio-inspired leaMike photocatalysts of ZnO-based nano-materials,holding potential applications in not only environmental purification but also solar-to-electric energy conversion.
