Aqueous zinc-ion batteries encounter issues with the formation of Zn dendrites and parasitic reactions at Zn anodes.To address these issues,coating Zn anodes with two-dimensional(2D)nanocarbon materials,such as graphe...Aqueous zinc-ion batteries encounter issues with the formation of Zn dendrites and parasitic reactions at Zn anodes.To address these issues,coating Zn anodes with two-dimensional(2D)nanocarbon materials,such as graphene,has proven effective in ensuring uniform current distribution and facilitating charge transfer.While direct growth of 2D nanocarbon on Zn substrates offers significant advantages,it remains challenging due to Zn's low melting point(420℃).In this study,as a first proof-ofconcept,a unique sonochemical route was developed to directly grow crystalline-amorphous mixed 2D nanocarbon films,named“Leopard-patterned graphene,”on Zn substrates.This unique structure provides uniform nucleation sites while maintaining high Zn^(2+) ion permeability,mitigating dendrite formation.In Zn symmetric coin cell tests,the Zn electrodes coated with Leopard-patterned graphene maintained stable cycling for over 2000 h at a constant current density of 3mA cm^(−2).This study introduces an innovative approach for bottom-up synthesis of 2D nanocarbon on Zn substrates under ambient conditions and demonstrates its potential to address critical challenges in Zn-ion battery performance.The findings provide insights into advanced electrode design strategies for next-generation energy storage devices.展开更多
The Al2O3（p）/Al nano-composites were fabricated from Al-K2ZrF6-Na2B4O7 system by sonochemistry in situ reaction. The fabrication mechanisms, including high intensity ultrasonic influence on microstructures and reinf...The Al2O3（p）/Al nano-composites were fabricated from Al-K2ZrF6-Na2B4O7 system by sonochemistry in situ reaction. The fabrication mechanisms, including high intensity ultrasonic influence on microstructures and reinforcement particles-aluminum matrix interface, were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The XRD results show that the component of the as-prepared composites is Al2O3 reinforcement. The SEM analysis results indicate that Al2O3 particles are uniformly distributed in the aluminum matrix. The TEM results show that the morphologies of Al2O3 particles present in nearly sphere-shape, the sizes are in the range of 20-100 nm, and the interfaces are net and no interfacial outgrowth is observed. Analysis with secondary development Image-J software shows that Al2O3 recoveries are firstly improved and then decreased with increasing ultrasonic power. When the power is 0.4 kW, the distribution is the best, and a maximum number of particles are obtained. The reaction mechanisms were investigated.展开更多
Derivatization has great potential for the high-value utilization of cellulose by enhancing its processability and functionality.However,due to the low reactivity of natural cellulose,it remains challenging to rapidly...Derivatization has great potential for the high-value utilization of cellulose by enhancing its processability and functionality.However,due to the low reactivity of natural cellulose,it remains challenging to rapidly prepare cellulose derivatives with high degrees of substitution.The“cavitation effect”of ultrasound can reduce the particle size and crystalline index of cellulose,which provides a possible method for preparing cellulose derivatives.Herein,a feasible method was proposed for efficiently converting regenerated cellulose to cellulose oleate with the assistance of ultrasonic treatment.By adjusting the reaction conditions including ultrasonic intensity,feeding ratios of oleic acid,reaction time,and reaction solvent,a series of cellulose oleates with degrees of substitution ranging from 0.37 to 1.71 were synthesized.Additionally,the effects of different reaction conditions on the chemical structures,crystalline structures,and thermal behaviors were investigated thoroughly.Cellulose oleates with degrees of substitution exceeding 1.23 exhibited amorphous structures and thermoplasticity with glass transition temperatures at 159.8 to 172.6℃.This study presented a sustainable and practicable method for effectively derivatizing cellulose.展开更多
In this paper, an ultrasound with frequency of 815 kHz was used to research the sonochemical yield in a small-size reverberation field by the method of fluorescent spectrum analysis. There are two characteristics on t...In this paper, an ultrasound with frequency of 815 kHz was used to research the sonochemical yield in a small-size reverberation field by the method of fluorescent spectrum analysis. There are two characteristics on the effect of sonochemistry in the reverberation field: First, the cavitation threshold was about 0.3 W / cm2 (it was 0.7 W / cm2 in travelling field); Second, when the sound intensity was larger than the threshold, the sonochemical yield increased as the intensity increased and increased rapidly after the intensity was at 1.69-2.13 W / cm2, so that there was a upturned point in the curve of the result (which would tend to saturation in the travelling field). The theoretical analysis shows that the reason of the threshold decrease is that the sound energy density becomes high in the reverberation field, and the upturned point results from the disturbance of the radiation pressure on the liquid surface. Therefore, by experiment and theory this paper shows that a reverberation field has to be built for the higher sonochemical yield.展开更多
Ag2S/Ag2WO4 composite microrods,with lengths of 0.2-1μm and diameters of 20-30 nm,were fabricated by a facile sonochemical route.The as-synthesized products were intensively investigated by a series of physicochemica...Ag2S/Ag2WO4 composite microrods,with lengths of 0.2-1μm and diameters of 20-30 nm,were fabricated by a facile sonochemical route.The as-synthesized products were intensively investigated by a series of physicochemical characterizations,such as N2 physical adsorption,X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Fourier transform infrared spectroscopy,diffuser reflectance spectroscopy,X-ray photoelectron spectroscopy,photoluminescence spectroscopy and photocurrent response measurements.Ultrasonic irradiation yields an obvious improvement in the photocatalyst texture,for example,an increase in crystallinity and surface area.Moreover,sonochemically fabricated Ag2S/Ag2WO4 microrods display strong visible light absorption and a high transient photocurrent response.The produced intimate Ag2S/Ag2WO4interface between Ag2S and Ag2WO4 crystal phases largely promotes the separation of photogenerated holes and electrons.High photocatalytic activity and stability were obtained over Ag2S/Ag2WO4composite microrods.The dye degradation rate constant of Ag2S/Ag2WO4 was 4.7 times and 29.8times higher than that of bare Ag2WO4 and Ag2S,respectively.展开更多
The reed pulping black liquor is used as a sample. Researches of (1) combined effect of ultrasound(US)/polyferric sulphate(PFS)/hydrogen peroxide(H 2O 2); (2) effects of the horn tip areas; (3) effect of dose of PFS w...The reed pulping black liquor is used as a sample. Researches of (1) combined effect of ultrasound(US)/polyferric sulphate(PFS)/hydrogen peroxide(H 2O 2); (2) effects of the horn tip areas; (3) effect of dose of PFS were carried. Extrapolation of these experiments indicated treatment results are possibly related to complex chemical compositions in the reed pulping black liquor.展开更多
Degradation effect of organic pollutant on pentachlorophenol(PCP) is researched by ultrasound. PCP is treated by low frequency(16 kHz) and high frequency(800±1 kHz), and bi frequency. The results of investigatio...Degradation effect of organic pollutant on pentachlorophenol(PCP) is researched by ultrasound. PCP is treated by low frequency(16 kHz) and high frequency(800±1 kHz), and bi frequency. The results of investigation on the ultrasonic destruction of PCP showed that the rate of PCP degradation at the same conditions is the highest at bi frequency, and the lowest at 16 kHz. In the presence of Fenton type reagent the degradation rate of PCP is the highest at bi frequency(20 93 times) as compared to the stirring system. This ratio is 4 91 and 1 06 at 800 kHz and 16 kHz, respectively. The studies showed the bi frequency is an effective method for pollutants degradation, but it is need make further study. Taking 800 kHz for example, under the same conditions, the smaller pH of the solution, the higher is the reaction rate. A similar situation applied to TOC, but the TOC removal lags behind degradation of PCP. This indicated the PCP is not completely mineralized. The ultrasound is somewhat enhanced for degradation of PCP and mineralization with only addition of CuSO 4, but the combination of ultrasound and Fenton type reagent is effective method for PCP degradation and mineralization. The rate of PCP degradation and TOC removal appeared to follow pseudo first order reaction kinetic law.展开更多
Sonochemical synthesis has flourished significantly in the last few decades for the preparation of photocatalysts.A large number of photocatalysts have been prepared through sonochemical techniques.This review highlig...Sonochemical synthesis has flourished significantly in the last few decades for the preparation of photocatalysts.A large number of photocatalysts have been prepared through sonochemical techniques.This review highlights the scope of sonochemistry in the preparation of photocatalysts,and their applications in energy production and environmental remediation.Beside,the sonochemical degradation of pollutants is discussed in detail.The progress made in sonochemical synthesis and the future perspective for this technique are summarized here.This review may create more enthusiasm among researchers to pay extra attention to the sonochemical synthesis of materials and add their useful contribution to the investigation of new materials for photocatalytic and other applications.This will propel this technique toward commercial sonosynthesis of nanomaterials.展开更多
The cycloaddition reaction of rosin and maleic anhydride under ultrasonic irradiation has been investigated. The results show that both isomerization and Diels-Alder cycloaddition reactions were accelerated remarkably...The cycloaddition reaction of rosin and maleic anhydride under ultrasonic irradiation has been investigated. The results show that both isomerization and Diels-Alder cycloaddition reactions were accelerated remarkably. The sonochemical reaction reached equilibrium in 5-10 min at 110℃, comparing with regular synthesis of 4-5 h over 180℃.展开更多
In situ Al2O3np/Al-Al11Ce3 nanocomposite was successfully synthesized from Al-CeO2 system using a novel two-step processing method that combines liquid-state mechanical mixing（step-Ⅰ） and sonochemistry melt reactio...In situ Al2O3np/Al-Al11Ce3 nanocomposite was successfully synthesized from Al-CeO2 system using a novel two-step processing method that combines liquid-state mechanical mixing（step-Ⅰ） and sonochemistry melt reaction（step-Ⅱ）. The microstructural evolution and mechanical properties were investigated by optical microscopy（OM）, scanning electron microscopy（SEM）, transmission electron spectroscopy（TEM） and tensile tests, respectively. A good spatial distribution of CeO2 particles in the Al melt was achieved due to reactive wetting during step-Ⅰ, and the following formation of Al2O3 np during step-Ⅱ was attributed to the cavitation-accelerated interfacial reaction. The solidified microstructure comprised uniformly dispersed Al2O3 np in the matrix and ultrafine lamellar Al-Al11Ce3 at the grain boundaries. Such unique microstructure endowed Al2O3np/Al-Al11Ce3 nanocomposite with a good balance between tensile strength（175 MPa） and ductility（18.5%）. The strengthening mechanisms of the nanocomposite included grain refinement, Orowan strengthening and quench strengthening, among which Orowan strengthening contributed the most to the yield strength of the nanocomposite.展开更多
Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflra...Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.展开更多
Silver nanoparticles (AgNPs) are directly grown on surface of ~25 μm copper wire by ultrasound-assisted chemical reduction. Silver nitrate is used as precursors, when polyvinylpyrrolidone (PVP) is added as a controll...Silver nanoparticles (AgNPs) are directly grown on surface of ~25 μm copper wire by ultrasound-assisted chemical reduction. Silver nitrate is used as precursors, when polyvinylpyrrolidone (PVP) is added as a controller of the dimension of AgNPs. Influence of growth parameters such as precursor's concentration, ratio proportion of PVP and ultra-sonication on the growth of AgNPs coating are determined. The best morphology, size of the AgNPs are observed on copper wire. The results show that the copper wire coated with AgNPs of^100 nm diameter exhibits good antioxidation and ohmic contact after sinter on Si substrate at a temperature as low as 320℃, is especially suitable as a substitute for silver paste electrode used in silicon solar cells.展开更多
A sonochemical method for the direct controlled synthesis of Cd-Bi nanoparticles from a bulk Cd-Bi alloy is introduced. The nanoparticles were found to be monodispersed and the size distribution can be easily controll...A sonochemical method for the direct controlled synthesis of Cd-Bi nanoparticles from a bulk Cd-Bi alloy is introduced. The nanoparticles were found to be monodispersed and the size distribution can be easily controlled by adjusting the ultrasonic power. The formation and the constituent of the as-prepared Cd-Bi nanoparticles were revealed by means of X-ray diffraction, differential thermal analysis and thermogravimetry, transmission electron microscopy, and electron diffraction. It was found that the Cd-Bi eutectic alloy nanoparticles are made of the hexagonal phase of metal cadmium and the rhombohedral phase of metal bismuth. In addition, we also found through tribological tests that the powder has an excellent antiwear property.展开更多
Polychlorinated biphenyl (PCB) is a kind of persistent and dangerous environmental pollutants. This paper presented the research result of sonochemical degradation of 2-chloro- biphenyl (2-CBP), 4-chlorobiphenyl (4-C...Polychlorinated biphenyl (PCB) is a kind of persistent and dangerous environmental pollutants. This paper presented the research result of sonochemical degradation of 2-chloro- biphenyl (2-CBP), 4-chlorobiphenyl (4-CBP) and 4,4-dichlorobiphenyl (4,4-CBP)in water. The ultrasonic degradation kinetics of 2-CBP, 4-CBP and 4,4-CBP in water were found to be first-order and the degradation rate coefficients are 3.69?0-2, 3.19?0-2 and 2.06?0-2 at 25?C for 2-CBP, 4-CBP and 4,4-CBP respectively. The influence of initial concentrations, reaction temperature on the ultrasonic decomposition of 2-CBP were also investigated.展开更多
The sonochemical effect of a bifrequency orthogonal ultrasonic irradiation has been studied by using two different detecting methods. It has been shown that the sonochemical yield produced by the bifrequency irradiati...The sonochemical effect of a bifrequency orthogonal ultrasonic irradiation has been studied by using two different detecting methods. It has been shown that the sonochemical yield produced by the bifrequency irradiation appears to be much more than the sum of the yields produced separately by the two irradiations. The bifrequency irradiation, therefore, can be expected to exert a great influence on the development of sonohemical展开更多
In this study we examined the cytotoxic effect of ZnO nanoparticles on various human cancer and normal cells.We found that the ZnO nanoparticles exerted a cytotoxic effect on the human glioma cell lines A172,U87,LNZ30...In this study we examined the cytotoxic effect of ZnO nanoparticles on various human cancer and normal cells.We found that the ZnO nanoparticles exerted a cytotoxic effect on the human glioma cell lines A172,U87,LNZ308,LN18,and LN229,whereas no cytotoxic effect was observed on normal human astrocytes.Similarly,the ZnO nanoparticles induced cell death in breast and prostate cancer cell lines while no major effect was observed in the respective normal breast and prostate cell lines.Using the fl uorescent dye 2,7-dichlorofl uorescein diacetate,we found that treatment of the glioma cells with ZnO nanoparticles induced a large increase in the generation of reactive oxygen species(ROS)and treatment of the cells with N-acetyl cysteine decreased the cytotoxic effect of the ZnO nanoparticles.In contrast,a smaller effect on ROS generation was observed in the normal astrocytes.These results suggest that ZnO nanoparticles may be employed as a selective cytotoxic agent for the eradication of cancer cells.展开更多
A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods,...A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemieal formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.展开更多
Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a n...Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a novel sonochemical approach to synthesize amorphous nickel-iron oxides/carbon nanohybrids with tunable compositions for the oxygen evolution reaction （OER）.The sonochemically synthesized amorphous electrocatalysts with optimal composition exhibit a low overpotential of 290 mV at 10 mA＆#183;cm-2 and a Tafel slope of 31 mV＆#183;decade-1 in a 0.1 M KOH electrolyte,outperforming the benchmark RuO2 catalyst.Meanwhile,these nanohybrids are also highly stable and remain amorphous even after prolonged cycling.In addition to amorphism,sonochemistry endows as-prepared nickel-iron oxides/carbon nanohybrids with a simultaneously formed carbon scaffold and internal Ni（0）,which can enhance the stability and activity for the OER.This work demonstrates that sonochemistry is a unique method for synthesizing amorphous metal oxides toward an efficient and durable OER.展开更多
基金supported by the Korean Institute of Energy Technology Evaluation and Planning (KETEP),Korean Government (MOTIE)(RS-2023-00303581)the National Research Foundation of Korea (NRF)the Ministry of Science and ICT (MIST)(Project Number:RS-2025-02223634)
文摘Aqueous zinc-ion batteries encounter issues with the formation of Zn dendrites and parasitic reactions at Zn anodes.To address these issues,coating Zn anodes with two-dimensional(2D)nanocarbon materials,such as graphene,has proven effective in ensuring uniform current distribution and facilitating charge transfer.While direct growth of 2D nanocarbon on Zn substrates offers significant advantages,it remains challenging due to Zn's low melting point(420℃).In this study,as a first proof-ofconcept,a unique sonochemical route was developed to directly grow crystalline-amorphous mixed 2D nanocarbon films,named“Leopard-patterned graphene,”on Zn substrates.This unique structure provides uniform nucleation sites while maintaining high Zn^(2+) ion permeability,mitigating dendrite formation.In Zn symmetric coin cell tests,the Zn electrodes coated with Leopard-patterned graphene maintained stable cycling for over 2000 h at a constant current density of 3mA cm^(−2).This study introduces an innovative approach for bottom-up synthesis of 2D nanocarbon on Zn substrates under ambient conditions and demonstrates its potential to address critical challenges in Zn-ion battery performance.The findings provide insights into advanced electrode design strategies for next-generation energy storage devices.
基金Project (50971066) supported by the National Natural Science Foundation of ChinaProject (20070299004) supported by the Research Fund for the Doctoral Program of Higher Education of China+1 种基金Project (2008-46) supported by the Jiangsu Provincial ‘333’ Project of training the High-level Talents Foundation, ChinaProject (BE2009127) supported by the Jiangsu Provincial Science Supporting Item, China
文摘The Al2O3（p）/Al nano-composites were fabricated from Al-K2ZrF6-Na2B4O7 system by sonochemistry in situ reaction. The fabrication mechanisms, including high intensity ultrasonic influence on microstructures and reinforcement particles-aluminum matrix interface, were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The XRD results show that the component of the as-prepared composites is Al2O3 reinforcement. The SEM analysis results indicate that Al2O3 particles are uniformly distributed in the aluminum matrix. The TEM results show that the morphologies of Al2O3 particles present in nearly sphere-shape, the sizes are in the range of 20-100 nm, and the interfaces are net and no interfacial outgrowth is observed. Analysis with secondary development Image-J software shows that Al2O3 recoveries are firstly improved and then decreased with increasing ultrasonic power. When the power is 0.4 kW, the distribution is the best, and a maximum number of particles are obtained. The reaction mechanisms were investigated.
基金The authors are grateful for financial support from the National Natural Science Foundation of China(Grant Nos.52273040 and 51873128)Yunnan Fundamental Research Projects(Grant No.202301AT070232).
文摘Derivatization has great potential for the high-value utilization of cellulose by enhancing its processability and functionality.However,due to the low reactivity of natural cellulose,it remains challenging to rapidly prepare cellulose derivatives with high degrees of substitution.The“cavitation effect”of ultrasound can reduce the particle size and crystalline index of cellulose,which provides a possible method for preparing cellulose derivatives.Herein,a feasible method was proposed for efficiently converting regenerated cellulose to cellulose oleate with the assistance of ultrasonic treatment.By adjusting the reaction conditions including ultrasonic intensity,feeding ratios of oleic acid,reaction time,and reaction solvent,a series of cellulose oleates with degrees of substitution ranging from 0.37 to 1.71 were synthesized.Additionally,the effects of different reaction conditions on the chemical structures,crystalline structures,and thermal behaviors were investigated thoroughly.Cellulose oleates with degrees of substitution exceeding 1.23 exhibited amorphous structures and thermoplasticity with glass transition temperatures at 159.8 to 172.6℃.This study presented a sustainable and practicable method for effectively derivatizing cellulose.
基金Project is supported by the National Natural Science foundation of China the work has been finished in the labouratory of Modern Acoustics,Nanjing University,Nanjing
文摘In this paper, an ultrasound with frequency of 815 kHz was used to research the sonochemical yield in a small-size reverberation field by the method of fluorescent spectrum analysis. There are two characteristics on the effect of sonochemistry in the reverberation field: First, the cavitation threshold was about 0.3 W / cm2 (it was 0.7 W / cm2 in travelling field); Second, when the sound intensity was larger than the threshold, the sonochemical yield increased as the intensity increased and increased rapidly after the intensity was at 1.69-2.13 W / cm2, so that there was a upturned point in the curve of the result (which would tend to saturation in the travelling field). The theoretical analysis shows that the reason of the threshold decrease is that the sound energy density becomes high in the reverberation field, and the upturned point results from the disturbance of the radiation pressure on the liquid surface. Therefore, by experiment and theory this paper shows that a reverberation field has to be built for the higher sonochemical yield.
基金supported by the National Natural Science Foundation of China(21567008,21263005)the Yangfan Project of Guangdong Province+2 种基金the Natural Science Foundation of Jiangxi Province(20133BAB21003,20161BAB203090)the Landing Project of Science and Technology of Colleges and Universities in Jiangxi Province(KJLD14046)the Graduate Innovation Project of Jiangxi Province(YC2015-S293)~~
文摘Ag2S/Ag2WO4 composite microrods,with lengths of 0.2-1μm and diameters of 20-30 nm,were fabricated by a facile sonochemical route.The as-synthesized products were intensively investigated by a series of physicochemical characterizations,such as N2 physical adsorption,X-ray diffraction,scanning electron microscopy,transmission electron microscopy,Fourier transform infrared spectroscopy,diffuser reflectance spectroscopy,X-ray photoelectron spectroscopy,photoluminescence spectroscopy and photocurrent response measurements.Ultrasonic irradiation yields an obvious improvement in the photocatalyst texture,for example,an increase in crystallinity and surface area.Moreover,sonochemically fabricated Ag2S/Ag2WO4 microrods display strong visible light absorption and a high transient photocurrent response.The produced intimate Ag2S/Ag2WO4interface between Ag2S and Ag2WO4 crystal phases largely promotes the separation of photogenerated holes and electrons.High photocatalytic activity and stability were obtained over Ag2S/Ag2WO4composite microrods.The dye degradation rate constant of Ag2S/Ag2WO4 was 4.7 times and 29.8times higher than that of bare Ag2WO4 and Ag2S,respectively.
文摘The reed pulping black liquor is used as a sample. Researches of (1) combined effect of ultrasound(US)/polyferric sulphate(PFS)/hydrogen peroxide(H 2O 2); (2) effects of the horn tip areas; (3) effect of dose of PFS were carried. Extrapolation of these experiments indicated treatment results are possibly related to complex chemical compositions in the reed pulping black liquor.
文摘Degradation effect of organic pollutant on pentachlorophenol(PCP) is researched by ultrasound. PCP is treated by low frequency(16 kHz) and high frequency(800±1 kHz), and bi frequency. The results of investigation on the ultrasonic destruction of PCP showed that the rate of PCP degradation at the same conditions is the highest at bi frequency, and the lowest at 16 kHz. In the presence of Fenton type reagent the degradation rate of PCP is the highest at bi frequency(20 93 times) as compared to the stirring system. This ratio is 4 91 and 1 06 at 800 kHz and 16 kHz, respectively. The studies showed the bi frequency is an effective method for pollutants degradation, but it is need make further study. Taking 800 kHz for example, under the same conditions, the smaller pH of the solution, the higher is the reaction rate. A similar situation applied to TOC, but the TOC removal lags behind degradation of PCP. This indicated the PCP is not completely mineralized. The ultrasound is somewhat enhanced for degradation of PCP and mineralization with only addition of CuSO 4, but the combination of ultrasound and Fenton type reagent is effective method for PCP degradation and mineralization. The rate of PCP degradation and TOC removal appeared to follow pseudo first order reaction kinetic law.
基金financially supported by National Science Foundation of China(No.51602207)。
文摘Sonochemical synthesis has flourished significantly in the last few decades for the preparation of photocatalysts.A large number of photocatalysts have been prepared through sonochemical techniques.This review highlights the scope of sonochemistry in the preparation of photocatalysts,and their applications in energy production and environmental remediation.Beside,the sonochemical degradation of pollutants is discussed in detail.The progress made in sonochemical synthesis and the future perspective for this technique are summarized here.This review may create more enthusiasm among researchers to pay extra attention to the sonochemical synthesis of materials and add their useful contribution to the investigation of new materials for photocatalytic and other applications.This will propel this technique toward commercial sonosynthesis of nanomaterials.
基金Supported by the Natural Science Foundation of Guangxi Province （0448020）, the Scientific Research Foundation for the Returned Overseas Chinese Scholars of State Education Ministry （2005-383）, and the Guangxi Talent Highland Program.
文摘The cycloaddition reaction of rosin and maleic anhydride under ultrasonic irradiation has been investigated. The results show that both isomerization and Diels-Alder cycloaddition reactions were accelerated remarkably. The sonochemical reaction reached equilibrium in 5-10 min at 110℃, comparing with regular synthesis of 4-5 h over 180℃.
基金Project supported by the National Natural Science Foundation of China(51174098)Open Project of Key Laboratory for Ecological-Environment Materials of Jiangsu Province(EML201208)
文摘In situ Al2O3np/Al-Al11Ce3 nanocomposite was successfully synthesized from Al-CeO2 system using a novel two-step processing method that combines liquid-state mechanical mixing（step-Ⅰ） and sonochemistry melt reaction（step-Ⅱ）. The microstructural evolution and mechanical properties were investigated by optical microscopy（OM）, scanning electron microscopy（SEM）, transmission electron spectroscopy（TEM） and tensile tests, respectively. A good spatial distribution of CeO2 particles in the Al melt was achieved due to reactive wetting during step-Ⅰ, and the following formation of Al2O3 np during step-Ⅱ was attributed to the cavitation-accelerated interfacial reaction. The solidified microstructure comprised uniformly dispersed Al2O3 np in the matrix and ultrafine lamellar Al-Al11Ce3 at the grain boundaries. Such unique microstructure endowed Al2O3np/Al-Al11Ce3 nanocomposite with a good balance between tensile strength（175 MPa） and ductility（18.5%）. The strengthening mechanisms of the nanocomposite included grain refinement, Orowan strengthening and quench strengthening, among which Orowan strengthening contributed the most to the yield strength of the nanocomposite.
基金supported by the National Basic Research Program of China (No.2012CB921504)the National Natural Science Foundation of China (No.11074127)
文摘Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.
基金financially supported by the National Natuie Science Foundation of China (No 11204082)Shanghai Natural Pond (No, 16ZR1410700)
文摘Silver nanoparticles (AgNPs) are directly grown on surface of ~25 μm copper wire by ultrasound-assisted chemical reduction. Silver nitrate is used as precursors, when polyvinylpyrrolidone (PVP) is added as a controller of the dimension of AgNPs. Influence of growth parameters such as precursor's concentration, ratio proportion of PVP and ultra-sonication on the growth of AgNPs coating are determined. The best morphology, size of the AgNPs are observed on copper wire. The results show that the copper wire coated with AgNPs of^100 nm diameter exhibits good antioxidation and ohmic contact after sinter on Si substrate at a temperature as low as 320℃, is especially suitable as a substitute for silver paste electrode used in silicon solar cells.
文摘A sonochemical method for the direct controlled synthesis of Cd-Bi nanoparticles from a bulk Cd-Bi alloy is introduced. The nanoparticles were found to be monodispersed and the size distribution can be easily controlled by adjusting the ultrasonic power. The formation and the constituent of the as-prepared Cd-Bi nanoparticles were revealed by means of X-ray diffraction, differential thermal analysis and thermogravimetry, transmission electron microscopy, and electron diffraction. It was found that the Cd-Bi eutectic alloy nanoparticles are made of the hexagonal phase of metal cadmium and the rhombohedral phase of metal bismuth. In addition, we also found through tribological tests that the powder has an excellent antiwear property.
基金financial support from the Natural Science Foundation of Shandong Province (No. Y98B03022) and the Foundation for University Key Teacher by the Ministry of Education(No. GG-630-11944-1006).
文摘Polychlorinated biphenyl (PCB) is a kind of persistent and dangerous environmental pollutants. This paper presented the research result of sonochemical degradation of 2-chloro- biphenyl (2-CBP), 4-chlorobiphenyl (4-CBP) and 4,4-dichlorobiphenyl (4,4-CBP)in water. The ultrasonic degradation kinetics of 2-CBP, 4-CBP and 4,4-CBP in water were found to be first-order and the degradation rate coefficients are 3.69?0-2, 3.19?0-2 and 2.06?0-2 at 25?C for 2-CBP, 4-CBP and 4,4-CBP respectively. The influence of initial concentrations, reaction temperature on the ultrasonic decomposition of 2-CBP were also investigated.
文摘The sonochemical effect of a bifrequency orthogonal ultrasonic irradiation has been studied by using two different detecting methods. It has been shown that the sonochemical yield produced by the bifrequency irradiation appears to be much more than the sum of the yields produced separately by the two irradiations. The bifrequency irradiation, therefore, can be expected to exert a great influence on the development of sonohemical
文摘In this study we examined the cytotoxic effect of ZnO nanoparticles on various human cancer and normal cells.We found that the ZnO nanoparticles exerted a cytotoxic effect on the human glioma cell lines A172,U87,LNZ308,LN18,and LN229,whereas no cytotoxic effect was observed on normal human astrocytes.Similarly,the ZnO nanoparticles induced cell death in breast and prostate cancer cell lines while no major effect was observed in the respective normal breast and prostate cell lines.Using the fl uorescent dye 2,7-dichlorofl uorescein diacetate,we found that treatment of the glioma cells with ZnO nanoparticles induced a large increase in the generation of reactive oxygen species(ROS)and treatment of the cells with N-acetyl cysteine decreased the cytotoxic effect of the ZnO nanoparticles.In contrast,a smaller effect on ROS generation was observed in the normal astrocytes.These results suggest that ZnO nanoparticles may be employed as a selective cytotoxic agent for the eradication of cancer cells.
基金supported by the National Natural Science Foundation of China (20805022, 21075061, 21121091)China Postdoctoral Science Foundation ( 20100471294)
文摘A clear understanding of the nucleation, growth, coarsening, the preparation of highly controlled nanostructures. Among and aggregation processes of nanomaterials is necessary to enable wet chemical synthetic methods, ultrasound-assisted preparation has become an important tool in material science. The formation and crystal growth mechanism under ultrasound is special compared with other wet chemical synthetic routes. In this review, we discussed the chemical and physical effect of ultrasound and summarized the ultrasonic effect on crystallization. The sonolysis of water and the cavitation-induced microjet impact and shockwave are the two key factors in the sonochemieal formation of inorganic nanomaterials. The ultrasonic-assisted Ostwald ripening and oriented attachment processes have been reviewed for the possible crystal growth mechanisms in the fabrication of inorganic nanostructures.
基金We thank the Photoemission Endstation （BL10B） in National Synchrotron Radiation Laboratory （NSRL） for collecting X-ray data. This work was supported by the National Key Basic Research Program of China （Nos. 2015CB351903 and 2014CB848900）, the National Natural Science Foundation of China （Nos. 21474095, 11574280, 11605201, and U1532112）, CAS Key Research Program of Frontier Sciences （No. QYZDB-SSW-SLH018）, and the Fundamental Research Funds for the Central Universities.
文摘Highly efficient and durable water oxidation electrocatalysts are critically important in a wide range of clean energy technologies,including water electrolyzers and rechargeable metal-air batteries.Here,we report a novel sonochemical approach to synthesize amorphous nickel-iron oxides/carbon nanohybrids with tunable compositions for the oxygen evolution reaction （OER）.The sonochemically synthesized amorphous electrocatalysts with optimal composition exhibit a low overpotential of 290 mV at 10 mA＆#183;cm-2 and a Tafel slope of 31 mV＆#183;decade-1 in a 0.1 M KOH electrolyte,outperforming the benchmark RuO2 catalyst.Meanwhile,these nanohybrids are also highly stable and remain amorphous even after prolonged cycling.In addition to amorphism,sonochemistry endows as-prepared nickel-iron oxides/carbon nanohybrids with a simultaneously formed carbon scaffold and internal Ni（0）,which can enhance the stability and activity for the OER.This work demonstrates that sonochemistry is a unique method for synthesizing amorphous metal oxides toward an efficient and durable OER.
