The activation of oxygen by ferrous(Fe^(2+))to generate·OH for contaminants degradation was inhibited due to the low utilization of oxygen,thus limiting its application in the practical environment.In this study,...The activation of oxygen by ferrous(Fe^(2+))to generate·OH for contaminants degradation was inhibited due to the low utilization of oxygen,thus limiting its application in the practical environment.In this study,with the superior oxygenation capacity of micro-nano bubbles(MNBs)and the stronger O_(2) activation capacity of Fe^(2+)-oxalate complexes,the MNBs/Fe^(2+)/oxalate(Ox)system was constructed with 4,4′-sulfonyldiphenol(BPS)as the main target emerging contaminants(ECs),and to investigate the enhancement contribution and reinforcement mechanism of the involvement of MNBs to the removal efficiency of ECs in the Fe^(2+)/Ox system.It was shown that the MNBs/Fe^(2+)/Ox system could effectively degrade four structurally diverse ECs.In this case,with BPS as the main target contaminant,adding MNBs could increase the BPS removal efficiency by about 35%.In the MNBs/Fe^(2+)/Ox system,the degradation rate of BPS depended on the concentration of Fe^(Ⅱ)(Ox)_(2)^(2-),while the extent of degradation was mainly governed by Fe^(Ⅱ)(Ox)_(2)^(2-)and Fe^(Ⅱ)(Ox)^(0).EPR and probe experiments showed that the reactive oxygen species(ROS)produced by the system and the iron hydroxide complexes produced by Fe^(3+)hydrolysis contributed to the degradation of BPS by oxidation and coagulation,respectively.In particular,·OH and O_(2)^(·-)were the main reactive oxygen species produced by this system.Moreover,the involvement of MNBs significantly increased the formation of ROS and iron hydroxide complexes in the Fe^(2+)/Ox system.The oxygenation process of MNBs used in this study enhanced the contaminants degradation performance of the Fe^(2+)/O_(x) system and has broadened the application scope of MNBs.展开更多
In this work,the gold nanoparticles（Au-NPs）were in-situ generated on the surface of MnO2nanosheets to form MnO2/Au-NPs nanocomposite in a simple and cost-effective way.Multiple experiments were carried out to optimi...In this work,the gold nanoparticles（Au-NPs）were in-situ generated on the surface of MnO2nanosheets to form MnO2/Au-NPs nanocomposite in a simple and cost-effective way.Multiple experiments were carried out to optimize the oxidation of basic dye（Methylene Blue（MB））,including the molar ratio of MnO2to chloroauric acid（HAu Cl4）,the p H of the solution and the effect of initial material.Under the optimal condition,the highest degradation efficiency for MB achieved to 98.9%within 60 min,which was obviously better than commercial MnO2powders（4.3%）and MnO2nanosheets（74.2%）.The enhanced oxidative degradation might attribute to the in-situ generation of ultra-small and highly-dispersed Au-NPs which enlarged the synergistic effect and/or interfacial effect between MnO2nanosheets and Au-NPs and facilitated the uptake of electrons by MnO2from MB during the oxidation,thus validating the application of MnO2/Au-NPs nanocomposite for direct removal of organic dyes from wastewater in a simple and convenient fashion.展开更多
An effective procedure has been developed to synthesize the functionalized graphene oxide grafted by maleic anhydride grafted liquid polybutadiene（MLPB-GO）. Fourier transform spectroscopy and X-ray photoelectron spe...An effective procedure has been developed to synthesize the functionalized graphene oxide grafted by maleic anhydride grafted liquid polybutadiene（MLPB-GO）. Fourier transform spectroscopy and X-ray photoelectron spectroscopy indicate the successful functionalization of GO. The NR/MLPB-GO composites were then prepared by the co-coagulation process. The results show that the mechanical properties of NR/MLPB-GO composites are obviously superior to those of NR/GO composites and neat NR. Compared with neat NR, the tensile strength, modulus at 300% strain and tear strength of NR composite containing 2.12 phr MLPB-GO are significantly increased by 40.5%, 109.1% and 85.0%, respectively. Dynamic mechanical analysis results show that 84% increase in storage modulus and 2.9 K enhancement in the glass transition temperature of the composite have been achieved with the incorporation of 2.12 phr MLPB-GO into NR. The good dispersion of GO and the strong interface interaction in the composites are responsible for the unprecedented reinforcing efficiency of MLPB-GO towards NR.展开更多
Because of profound applications of two-dimensional molybdenum disulfide(MoS_(2))and its heterostructures in electronics,its thermal stability has been spurred substantial interest.We employ a precision muffle furnace...Because of profound applications of two-dimensional molybdenum disulfide(MoS_(2))and its heterostructures in electronics,its thermal stability has been spurred substantial interest.We employ a precision muffle furnace at a series of increasing temperatures up to 340℃to study the oxidation behavior of continuous MoS_(2)films by either directly growing mono-and fewlayer MoS_(2)on SiO_(2)/Si substrate,or by mechanically transferring monolayer MoS_(2)or hexagonal boron nitride(h-BN)onto monolayer MoS_(2)substrate.Results show that monolayer MoS_(2)can withstand high temperature at 340℃with less oxidation while the few-layer MoS_(2)films are completely oxidized just at 280℃,resulting from the growth-induced tensile strain in few-layer MoS_(2).When the tensile strain of films is released by transfer method,the stacked few-layer MoS_(2)films exhibit superior thermal stability and typical layer-by-layer oxidation behavior at similarly high temperature.Counterintuitively,for the MoS_(2)/h-BN heterostructure,the h-BN film itself stacked on top is not damaged and forms many bubbles at 340℃,whereas the underlying monolayer MoS_(2)film is oxidized completely.By comprehensively using various experimental characterization and molecular dynamics calculations,such anomalous oxidation behavior of MoS_(2)/h-BN heterostructure is mainly due to the increased tensile strain in MoS_(2)film at elevated temperature.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52470014 and 52370100)the Department of Education of Gansu Province(China):Major Cultivation Project of Scientific Research Innovation Platform in University(No.2024CXPT-14).
文摘The activation of oxygen by ferrous(Fe^(2+))to generate·OH for contaminants degradation was inhibited due to the low utilization of oxygen,thus limiting its application in the practical environment.In this study,with the superior oxygenation capacity of micro-nano bubbles(MNBs)and the stronger O_(2) activation capacity of Fe^(2+)-oxalate complexes,the MNBs/Fe^(2+)/oxalate(Ox)system was constructed with 4,4′-sulfonyldiphenol(BPS)as the main target emerging contaminants(ECs),and to investigate the enhancement contribution and reinforcement mechanism of the involvement of MNBs to the removal efficiency of ECs in the Fe^(2+)/Ox system.It was shown that the MNBs/Fe^(2+)/Ox system could effectively degrade four structurally diverse ECs.In this case,with BPS as the main target contaminant,adding MNBs could increase the BPS removal efficiency by about 35%.In the MNBs/Fe^(2+)/Ox system,the degradation rate of BPS depended on the concentration of Fe^(Ⅱ)(Ox)_(2)^(2-),while the extent of degradation was mainly governed by Fe^(Ⅱ)(Ox)_(2)^(2-)and Fe^(Ⅱ)(Ox)^(0).EPR and probe experiments showed that the reactive oxygen species(ROS)produced by the system and the iron hydroxide complexes produced by Fe^(3+)hydrolysis contributed to the degradation of BPS by oxidation and coagulation,respectively.In particular,·OH and O_(2)^(·-)were the main reactive oxygen species produced by this system.Moreover,the involvement of MNBs significantly increased the formation of ROS and iron hydroxide complexes in the Fe^(2+)/Ox system.The oxygenation process of MNBs used in this study enhanced the contaminants degradation performance of the Fe^(2+)/O_(x) system and has broadened the application scope of MNBs.
基金supported by the National Natural Science Foundation of China (Nos. 21277048 and 21505046)the China Postdoctoral Science Foundation (No. 2016 M590336)+1 种基金the "Chenguang Program" funded by Shanghai Education Development FoundationShanghai Municipal Education Commission (No. 15CG21)
文摘In this work,the gold nanoparticles（Au-NPs）were in-situ generated on the surface of MnO2nanosheets to form MnO2/Au-NPs nanocomposite in a simple and cost-effective way.Multiple experiments were carried out to optimize the oxidation of basic dye（Methylene Blue（MB））,including the molar ratio of MnO2to chloroauric acid（HAu Cl4）,the p H of the solution and the effect of initial material.Under the optimal condition,the highest degradation efficiency for MB achieved to 98.9%within 60 min,which was obviously better than commercial MnO2powders（4.3%）and MnO2nanosheets（74.2%）.The enhanced oxidative degradation might attribute to the in-situ generation of ultra-small and highly-dispersed Au-NPs which enlarged the synergistic effect and/or interfacial effect between MnO2nanosheets and Au-NPs and facilitated the uptake of electrons by MnO2from MB during the oxidation,thus validating the application of MnO2/Au-NPs nanocomposite for direct removal of organic dyes from wastewater in a simple and convenient fashion.
基金financially supported by the National Natural Science Foundation of China(No.51363006)Science and Technology innovation key project of Hainan province(No.ZDXM20120090)National Science and Technology support project(No.2013BAF08B02)
文摘An effective procedure has been developed to synthesize the functionalized graphene oxide grafted by maleic anhydride grafted liquid polybutadiene（MLPB-GO）. Fourier transform spectroscopy and X-ray photoelectron spectroscopy indicate the successful functionalization of GO. The NR/MLPB-GO composites were then prepared by the co-coagulation process. The results show that the mechanical properties of NR/MLPB-GO composites are obviously superior to those of NR/GO composites and neat NR. Compared with neat NR, the tensile strength, modulus at 300% strain and tear strength of NR composite containing 2.12 phr MLPB-GO are significantly increased by 40.5%, 109.1% and 85.0%, respectively. Dynamic mechanical analysis results show that 84% increase in storage modulus and 2.9 K enhancement in the glass transition temperature of the composite have been achieved with the incorporation of 2.12 phr MLPB-GO into NR. The good dispersion of GO and the strong interface interaction in the composites are responsible for the unprecedented reinforcing efficiency of MLPB-GO towards NR.
基金the National Natural Science Foundation of China(No.52005489)Ningbo 3315 Innovation Team(No.2020A-03-C)+1 种基金the China Postdoctoral Science Fund(Nos.2021T140685 and 2019M662126)the Natural Science Foundation of Zhejiang Province(No.LR20E050001).
文摘Because of profound applications of two-dimensional molybdenum disulfide(MoS_(2))and its heterostructures in electronics,its thermal stability has been spurred substantial interest.We employ a precision muffle furnace at a series of increasing temperatures up to 340℃to study the oxidation behavior of continuous MoS_(2)films by either directly growing mono-and fewlayer MoS_(2)on SiO_(2)/Si substrate,or by mechanically transferring monolayer MoS_(2)or hexagonal boron nitride(h-BN)onto monolayer MoS_(2)substrate.Results show that monolayer MoS_(2)can withstand high temperature at 340℃with less oxidation while the few-layer MoS_(2)films are completely oxidized just at 280℃,resulting from the growth-induced tensile strain in few-layer MoS_(2).When the tensile strain of films is released by transfer method,the stacked few-layer MoS_(2)films exhibit superior thermal stability and typical layer-by-layer oxidation behavior at similarly high temperature.Counterintuitively,for the MoS_(2)/h-BN heterostructure,the h-BN film itself stacked on top is not damaged and forms many bubbles at 340℃,whereas the underlying monolayer MoS_(2)film is oxidized completely.By comprehensively using various experimental characterization and molecular dynamics calculations,such anomalous oxidation behavior of MoS_(2)/h-BN heterostructure is mainly due to the increased tensile strain in MoS_(2)film at elevated temperature.
