The morphology and heterojunction engineering are effective ways to boost the performance of Cubased catalysts. Herein, we have reported the designed synthesis of two-dimensional Cu-Cu O heterojunction nanosheets(2D C...The morphology and heterojunction engineering are effective ways to boost the performance of Cubased catalysts. Herein, we have reported the designed synthesis of two-dimensional Cu-Cu O heterojunction nanosheets(2D Cu-Cu O NS) based on 3-aminopropyl-triethoxysilane(APTES, KH550) aided synthetic strategy. The APTES can act as both the ligand and alkali(-OH) source to guide the large-scale synthesis of 2D Cu-based precursor, which can transform into 2D Cu-Cu O NS by the controllable post-treatment.The Si species from APTES can protect the particles from the severe aggregation and growth, guaranteeing the formation of 2D sheets composed of small-sized Cu-Cu O heterojunction(about 20 nm). The heterojunction interfaces can provide plentiful active sites to boost the catalytic ability. The 2D sheets can provide large accessible surface, being conducive to the contact of the catalyst and reactants. Benefiting from above virtues, the 2D Cu-Cu O NS showed the superior catalytic performance for the reduction of a series of nitro compounds, being superior to most reported non-noble metal-based catalysts. Notably,it exhibited good re-cycled performance with no obvious performance degradation after 10 consecutive catalysis. The present study will be promising to promote the application of the Cu-based catalysts, due to its ability to control the morphology and potential for the large-scale synthesis.展开更多
Microorganims of the bovine rumen fluid biocatalyzed the reduction of nitro-compound substrates to yield the respective amines. This enzymatic process, using ruminal contents, has rarely been reported in associa- tion...Microorganims of the bovine rumen fluid biocatalyzed the reduction of nitro-compound substrates to yield the respective amines. This enzymatic process, using ruminal contents, has rarely been reported in associa- tion with the bioreduction of nitro groups. The biotransformation reactions catalyzed by this system were de- pendent of both the electronic characteristics and the area/volume of the nitro-substrates confirming the processes are enzymatic. The semi-preparative scale biotransformation went by in good yield showing the rumen fluid may be employed in the synthesis of amines under very mild conditions and, moreover, it may have application in the bioremediation of nitro-compounds.展开更多
Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild veg...Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild vegetation were surveyed in Abu Tartur mining area located in the Southern part of Western depending essentially on the seepage from water line tubes which supplies water demands at Abu Tartur. The vegetation-environment relationships in Abu Tartur are described. Data sets （42 species in 38 plots） beside the pip-line enriched from 13 wells were analyzed, using multivariate procedures, i.e., two-way indicator species analysis （TW1NSPAN）, detrended correspondence analysis （DCA） and detrended canonical correspondence analysis （CCA）, to produce a classification of plant communities in the studied areas and to examine the relationships of that plant communities to certain edaphic factors. Five plant communities were identified. Astragalus vogelii, Chenopodium murale, Citrullus colocynthis, Fagonia arabica, Farsetia aegyptia, Hyoscyamus muticus, Morettia philaeana, Cynodon dactylon, Trichodesma africana, Tarnarix nilotica, Senna italica, Schouwia purpurea, Salsola volkensii and Phragmites australis were common in the study area. Phytochemical survey for nitroprpionic compounds in some taxa belonging to Fabaceae family showed the absence of these toxic compounds by using GC/MS analysis. Also some phytochemical components ofAstragalus vogalii were extracted and identified by GC/MS spectra. A biological activity, in this regard was the screening of methanol extracts for some wild taxa of Abu Tartur against natural Tetranychus urticae as acricidal activity and the methanol extracts of some taxa give high mortality results, like Farsetia aegyptia （86.6%） and Fagonia arabica Burm. f. （70.0%）.展开更多
MXene is a new type of layered two-dimensional transition metal carbide materials differing from graphene, demonstrating intriguing chemical/physical properties. Here the chemical modification of MXene and next fabric...MXene is a new type of layered two-dimensional transition metal carbide materials differing from graphene, demonstrating intriguing chemical/physical properties. Here the chemical modification of MXene and next fabrication of core-shell MXene-COOH@(PEI/PAA)_n composites have been investigated. The obtained MXene-based composites were treated with gold nanoparticles to form MXene—COOH@(PEI/PAA)_n@AuNPs nanocomposites, and their catalytic properties for nitro-compounds were studied. The prepared nanocomposites demonstrated good catalytic activity and reproducibility, showing potential applications in composite catalysts and environmental fields.展开更多
MXene, a new type of two-dimensional layered transition metal carbide material differing from graphene, demonstrates intriguing chemical/physical properties and wide applications in recent years. Here, the preparation...MXene, a new type of two-dimensional layered transition metal carbide material differing from graphene, demonstrates intriguing chemical/physical properties and wide applications in recent years. Here, the preparation of the self-assembled MXene-gold nanoparticles (MXene@AuNPs) nanocomposites with tunable sizes is reported. The nano- composites are obtained via the self-reduction reactions of MXene material in a HAuCI4 solution at room temperature. The sizes of the Au particles can be well-controlled by reg- ulating the self-reduction reaction time. They can greatly in- fluence the catalytic behaviors of the MXene@AuNPs composites. MXene@AuNPs composites with optimized re- duction time show high catalytic performances and good cycle stability for model catalytic reactions of nRro-compounds, such as 2-nitrophenol and 4-nitrophenol. This work demon- strates a new approach for the preparation of tunable MXene- based self-assembled composites.展开更多
Poly(triphenylamine-p-phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation.The structures of two copoly-mers were characterized.Ultraviolet and visible spectro-scopy(UV-Vis...Poly(triphenylamine-p-phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation.The structures of two copoly-mers were characterized.Ultraviolet and visible spectro-scopy(UV-Vis)and photoluminescence(PL)spectra show the end-capped polymer emits intensive green light in both solution and film state.Their applications in the detection of nitro compounds were investigated,and the results show high fluorescence quenching sensitivity of the end-capped polymer towards o-nitrotoluene(o-NT).When the concentration of o-NT was 21.5×10^(-3) mol/L,the fluorescence quenching reached 96%.Additionally,after the exposure of polymer film in three different quenchers such as dinitrotoluene(DNT),p-nitrobenzo-quinone(p-BQ)and p-nitrotoluene(p-NT)for 600 s,its fluorescence quenching reached 93.6%,11.5%and 77.9%,respectively.This kind of polymer has great advantages in preparation and may find applications in the detection of nitro explosives.展开更多
基金the support of this research by the National Natural Science Foundation of China (No. 91961111)the Natural Science Foundation of Heilongjiang Province (No. ZD2021B003)。
文摘The morphology and heterojunction engineering are effective ways to boost the performance of Cubased catalysts. Herein, we have reported the designed synthesis of two-dimensional Cu-Cu O heterojunction nanosheets(2D Cu-Cu O NS) based on 3-aminopropyl-triethoxysilane(APTES, KH550) aided synthetic strategy. The APTES can act as both the ligand and alkali(-OH) source to guide the large-scale synthesis of 2D Cu-based precursor, which can transform into 2D Cu-Cu O NS by the controllable post-treatment.The Si species from APTES can protect the particles from the severe aggregation and growth, guaranteeing the formation of 2D sheets composed of small-sized Cu-Cu O heterojunction(about 20 nm). The heterojunction interfaces can provide plentiful active sites to boost the catalytic ability. The 2D sheets can provide large accessible surface, being conducive to the contact of the catalyst and reactants. Benefiting from above virtues, the 2D Cu-Cu O NS showed the superior catalytic performance for the reduction of a series of nitro compounds, being superior to most reported non-noble metal-based catalysts. Notably,it exhibited good re-cycled performance with no obvious performance degradation after 10 consecutive catalysis. The present study will be promising to promote the application of the Cu-based catalysts, due to its ability to control the morphology and potential for the large-scale synthesis.
文摘Microorganims of the bovine rumen fluid biocatalyzed the reduction of nitro-compound substrates to yield the respective amines. This enzymatic process, using ruminal contents, has rarely been reported in associa- tion with the bioreduction of nitro groups. The biotransformation reactions catalyzed by this system were de- pendent of both the electronic characteristics and the area/volume of the nitro-substrates confirming the processes are enzymatic. The semi-preparative scale biotransformation went by in good yield showing the rumen fluid may be employed in the synthesis of amines under very mild conditions and, moreover, it may have application in the bioremediation of nitro-compounds.
文摘Groundwater in Egypt plays an important role in the country＇s water budget. South Western desert represent an arid of desert biome within world＇s net-work of the biosphere reserves. In this study, the plant wild vegetation were surveyed in Abu Tartur mining area located in the Southern part of Western depending essentially on the seepage from water line tubes which supplies water demands at Abu Tartur. The vegetation-environment relationships in Abu Tartur are described. Data sets （42 species in 38 plots） beside the pip-line enriched from 13 wells were analyzed, using multivariate procedures, i.e., two-way indicator species analysis （TW1NSPAN）, detrended correspondence analysis （DCA） and detrended canonical correspondence analysis （CCA）, to produce a classification of plant communities in the studied areas and to examine the relationships of that plant communities to certain edaphic factors. Five plant communities were identified. Astragalus vogelii, Chenopodium murale, Citrullus colocynthis, Fagonia arabica, Farsetia aegyptia, Hyoscyamus muticus, Morettia philaeana, Cynodon dactylon, Trichodesma africana, Tarnarix nilotica, Senna italica, Schouwia purpurea, Salsola volkensii and Phragmites australis were common in the study area. Phytochemical survey for nitroprpionic compounds in some taxa belonging to Fabaceae family showed the absence of these toxic compounds by using GC/MS analysis. Also some phytochemical components ofAstragalus vogalii were extracted and identified by GC/MS spectra. A biological activity, in this regard was the screening of methanol extracts for some wild taxa of Abu Tartur against natural Tetranychus urticae as acricidal activity and the methanol extracts of some taxa give high mortality results, like Farsetia aegyptia （86.6%） and Fagonia arabica Burm. f. （70.0%）.
基金financially supported by the National Natural Science Foundation of China (Nos.21473153 and 51771162)Support Program for the Top Young Talents of Hebei Province,China Postdoctoral Science Foundation (No.2015M580214)+1 种基金the Scientific and Technological Research and Development Program of Qinhuangdao City (No.201701B004)Undergraduate Training Programs for Innovation and Entrepreneurship of Yanshan University (No.CXXL2017227)
文摘MXene is a new type of layered two-dimensional transition metal carbide materials differing from graphene, demonstrating intriguing chemical/physical properties. Here the chemical modification of MXene and next fabrication of core-shell MXene-COOH@(PEI/PAA)_n composites have been investigated. The obtained MXene-based composites were treated with gold nanoparticles to form MXene—COOH@(PEI/PAA)_n@AuNPs nanocomposites, and their catalytic properties for nitro-compounds were studied. The prepared nanocomposites demonstrated good catalytic activity and reproducibility, showing potential applications in composite catalysts and environmental fields.
基金supported by the National Natural Science Foundation of China (21473153 and 51771162)Support Program for the Top Young Talents of Hebei Province, China Postdoctoral Science Foundation (2015M580214)the Scientific and Technological Research and Development Program of Qinhuangdao City (201701B004)
文摘MXene, a new type of two-dimensional layered transition metal carbide material differing from graphene, demonstrates intriguing chemical/physical properties and wide applications in recent years. Here, the preparation of the self-assembled MXene-gold nanoparticles (MXene@AuNPs) nanocomposites with tunable sizes is reported. The nano- composites are obtained via the self-reduction reactions of MXene material in a HAuCI4 solution at room temperature. The sizes of the Au particles can be well-controlled by reg- ulating the self-reduction reaction time. They can greatly in- fluence the catalytic behaviors of the MXene@AuNPs composites. MXene@AuNPs composites with optimized re- duction time show high catalytic performances and good cycle stability for model catalytic reactions of nRro-compounds, such as 2-nitrophenol and 4-nitrophenol. This work demon- strates a new approach for the preparation of tunable MXene- based self-assembled composites.
基金supported by the Key National Science Foundation of China(No.20736002)the National Natural Science Foundation of China(Grant No.20776045)the Science Foundation of Shanghai Government(07ZR14029).
文摘Poly(triphenylamine-p-phenylenevinylene)s with two different end-groups were obtained through a Wittig polycondensation.The structures of two copoly-mers were characterized.Ultraviolet and visible spectro-scopy(UV-Vis)and photoluminescence(PL)spectra show the end-capped polymer emits intensive green light in both solution and film state.Their applications in the detection of nitro compounds were investigated,and the results show high fluorescence quenching sensitivity of the end-capped polymer towards o-nitrotoluene(o-NT).When the concentration of o-NT was 21.5×10^(-3) mol/L,the fluorescence quenching reached 96%.Additionally,after the exposure of polymer film in three different quenchers such as dinitrotoluene(DNT),p-nitrobenzo-quinone(p-BQ)and p-nitrotoluene(p-NT)for 600 s,its fluorescence quenching reached 93.6%,11.5%and 77.9%,respectively.This kind of polymer has great advantages in preparation and may find applications in the detection of nitro explosives.
