Of several noble metal nanoparticles,silver nanoparticles(AgNPs)have attracted special attention due to their distinct properties,such as favorable electrical conductivity,chemical stability,and catalytic and antibact...Of several noble metal nanoparticles,silver nanoparticles(AgNPs)have attracted special attention due to their distinct properties,such as favorable electrical conductivity,chemical stability,and catalytic and antibacterial activities.Green synthesis of AgNPs using plant extracts containing phytochemical agents has attracted considerable interest.This environmentally friendly approach is more biocompatible and costefficient and has the capability of supporting large-scale synthesis.This study developed an eco-friendly method for the preparation of AgNPs using the aqueous leaf extract of Saussurea obvallata as reducing and capping agents.Ultraviolet visible spectroscopy(UV-is),Fourier transform infrared spectroscopy(FTIR),Raman,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)analyses were conducted to characterize the synthesized AgNPs.The morphology of AgNPs was found to be spherical with an average crystallite size of 12 nm and a maximum absorbance at 410 nm.10 mg of AgNPs had potential to reduce 4-nitrophenol to 4-aminophenol in 16 min and exhibited strong biological activities against the Gram-negative bacteria Escherichia coli(12 mm)and Gram-positive bacteria Enterococcus faecalis(13 mm).The antioxidant activity of the synthesized AgNPs was investigated against the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging and exhibited up to 61.21%±0.02%at an AgNPs concentration of 500 mg/mL.展开更多
A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions ca...A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions can be used for the synthesis of drugs and biologically active organic compound of arsenic, antimony and bismuth. A possible new mechanism of the reaction is proposed.展开更多
To study the physical and chemical properties of uranium catalyst by impregnation and calcination us was first obtained uranium catalyst SAPO-U, Nd, Sb, Bi. The method of X-ray structure has been studied of the uraniu...To study the physical and chemical properties of uranium catalyst by impregnation and calcination us was first obtained uranium catalyst SAPO-U, Nd, Sb, Bi. The method of X-ray structure has been studied of the uranium catalyst SAPO-U, Nd, Sb, Bi.展开更多
The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanu...The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanuric chloride in the presence of Na2CO3 followed by the addition of trityl aniline. Solution and solid state fluorescence demonstrated a strong blue/purple emission centered at 450 nm. 1H-NMR spectroscopy, mass spectrometry analysis, elemental analysis, and DOSY-NMR were used for the characterization of the fluorophore.展开更多
The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Res...The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Results of field tests have shown high efficiency of the catalyst ＂Mukhamedzhan- 1＂ for detoxification UDMH.展开更多
Recently, much attention has been devoted to new methods of intensifying situ leaching of uranium using a variety of oxidants. Currently, there are many new types of oxidants. Therefore, the development and introducti...Recently, much attention has been devoted to new methods of intensifying situ leaching of uranium using a variety of oxidants. Currently, there are many new types of oxidants. Therefore, the development and introduction of new methods for the catalytic oxidation of U4＋ to U6＋ is urgent. Objective for development of new technology of catalytic oxidation of U4＋ to U6＋ catalyst ＂Muhamedzhan-1＂ is that will reduce the consumption of sulfuric acid, hydrogen peroxide acidification.展开更多
Organic-inorganic halide perovskites have significant potential for application in next-generation solar cells.However,their applications are limited by challenges associated with large-area processability and long-te...Organic-inorganic halide perovskites have significant potential for application in next-generation solar cells.However,their applications are limited by challenges associated with large-area processability and long-term stability owing to the presence of pinholes and defect sites.Here,we incorporated cesium formate in a perovskite active layer using a sequential perovskite fabrication process to eliminate the defect sites of perovskites and improve the film processability via roll-to-roll(R2R)processing.The addition of cesium formate salt to the PbI2 layer influences the perovskite crystal formation behavior as well as increases the perovskite crystallinity and decreases the defect density.Furthermore,cesium formate addition eliminated small PbI2 grains and smoothed the perovskite surface,resulting in a large crystal grain size.The formate ions interact with the PbI2 component and passivate halide vacancy defects,reducing nonradiative recombination and improving charge transfer.Additionally,the treated perovskite films were highly stable in air,exhibiting improved efficiency retention over time and achieving a power conversion efficiency(PCE)of>22%compared to the control.Furthermore,the additive-treated perovskite film was processed using the R2R method,achieving a high PCE of>14%with minimal hysteresis.展开更多
文摘Of several noble metal nanoparticles,silver nanoparticles(AgNPs)have attracted special attention due to their distinct properties,such as favorable electrical conductivity,chemical stability,and catalytic and antibacterial activities.Green synthesis of AgNPs using plant extracts containing phytochemical agents has attracted considerable interest.This environmentally friendly approach is more biocompatible and costefficient and has the capability of supporting large-scale synthesis.This study developed an eco-friendly method for the preparation of AgNPs using the aqueous leaf extract of Saussurea obvallata as reducing and capping agents.Ultraviolet visible spectroscopy(UV-is),Fourier transform infrared spectroscopy(FTIR),Raman,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)analyses were conducted to characterize the synthesized AgNPs.The morphology of AgNPs was found to be spherical with an average crystallite size of 12 nm and a maximum absorbance at 410 nm.10 mg of AgNPs had potential to reduce 4-nitrophenol to 4-aminophenol in 16 min and exhibited strong biological activities against the Gram-negative bacteria Escherichia coli(12 mm)and Gram-positive bacteria Enterococcus faecalis(13 mm).The antioxidant activity of the synthesized AgNPs was investigated against the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical scavenging and exhibited up to 61.21%±0.02%at an AgNPs concentration of 500 mg/mL.
文摘A new approach modification reactions Atherton-Todd, Betty, Mannich and Doebner reactions with of arsine, stibine and bismuthine have been proposed in organometallic chemistry of these elements. These new reactions can be used for the synthesis of drugs and biologically active organic compound of arsenic, antimony and bismuth. A possible new mechanism of the reaction is proposed.
文摘To study the physical and chemical properties of uranium catalyst by impregnation and calcination us was first obtained uranium catalyst SAPO-U, Nd, Sb, Bi. The method of X-ray structure has been studied of the uranium catalyst SAPO-U, Nd, Sb, Bi.
文摘The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanuric chloride in the presence of Na2CO3 followed by the addition of trityl aniline. Solution and solid state fluorescence demonstrated a strong blue/purple emission centered at 450 nm. 1H-NMR spectroscopy, mass spectrometry analysis, elemental analysis, and DOSY-NMR were used for the characterization of the fluorophore.
文摘The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Results of field tests have shown high efficiency of the catalyst ＂Mukhamedzhan- 1＂ for detoxification UDMH.
文摘Recently, much attention has been devoted to new methods of intensifying situ leaching of uranium using a variety of oxidants. Currently, there are many new types of oxidants. Therefore, the development and introduction of new methods for the catalytic oxidation of U4＋ to U6＋ is urgent. Objective for development of new technology of catalytic oxidation of U4＋ to U6＋ catalyst ＂Muhamedzhan-1＂ is that will reduce the consumption of sulfuric acid, hydrogen peroxide acidification.
基金the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2021R1C1C1012188),(No.2022M3J7A1066428)KK2352-20 funded by the Development of Platform Technology for Industrial Support based on Public-Infra.
文摘Organic-inorganic halide perovskites have significant potential for application in next-generation solar cells.However,their applications are limited by challenges associated with large-area processability and long-term stability owing to the presence of pinholes and defect sites.Here,we incorporated cesium formate in a perovskite active layer using a sequential perovskite fabrication process to eliminate the defect sites of perovskites and improve the film processability via roll-to-roll(R2R)processing.The addition of cesium formate salt to the PbI2 layer influences the perovskite crystal formation behavior as well as increases the perovskite crystallinity and decreases the defect density.Furthermore,cesium formate addition eliminated small PbI2 grains and smoothed the perovskite surface,resulting in a large crystal grain size.The formate ions interact with the PbI2 component and passivate halide vacancy defects,reducing nonradiative recombination and improving charge transfer.Additionally,the treated perovskite films were highly stable in air,exhibiting improved efficiency retention over time and achieving a power conversion efficiency(PCE)of>22%compared to the control.Furthermore,the additive-treated perovskite film was processed using the R2R method,achieving a high PCE of>14%with minimal hysteresis.
