Dust particles emitted from smelters can be hazardous to ecosystems and humans,as they are often enriched in metallic compounds.Here,we combined multi-method mineralogical analysis with a sophisticated size sorting ap...Dust particles emitted from smelters can be hazardous to ecosystems and humans,as they are often enriched in metallic compounds.Here,we combined multi-method mineralogical analysis with a sophisticated size sorting approach for copper smelting dust to study the nanosize-effect on heavy metal distribution,which has hitherto been underestimated.Three types of dust were collected from a copper flash smelter and then size-sorted using a Dekati low-pressure impactor.Results showed that all three samples could easily sort out nanoscale dust particles(<1μm,grades 10–2)and even those smaller than 100 nm(grades 5–2).Especially for electrostatic precipitators dust,the mass fraction of nanoscale dust(<1μm)could reach 10.71%.The presence of heavy metals(Pb,Zn,Cu,and As)and their mineral species in dust was examined at various particle sizes.It was discovered that different heavy metals are enriched on nanoparticles in specific sizes.In micron-sized particles,heavy metals are generally found in discrete phases(e.g.,CuSO_(4),PbSO_(4),and As_(2)O_(3)).In nanoscale particles,the dominant phase is Fe_(3)O_(4),while heavy metals are mostly found in lattice substitution(e.g.,CuFe_(2)O_(4)and ZnFe_(2)O_(4)).Two distinct nano-dust morphologies were found:One with irregular mesh or chain structures consisting of particles of a few nanometers,and the other with polygonal crystals in larger sizes of hundreds of nanometers.The enrichment of heavy metals in the latter morphology is more pronounced,possibly because lattice substitution of heavy metals is more likely to occur when polycrystalline particles are formed.展开更多
The rapid development of internet and internet of things brings new opportunities for the expansion of intelligent sensors,and acetone as a major disease detection indicator(i.e.,diabetes)making it become extremely im...The rapid development of internet and internet of things brings new opportunities for the expansion of intelligent sensors,and acetone as a major disease detection indicator(i.e.,diabetes)making it become extremely important clinical indicator.Herein,uniform mesoporous ZnO spheres were successfully synthesized via novel formaldehyde-assisted metal-ligand crosslinking strategy.In order to adjust the pore structure of mesoporous ZnO,various mesoporous ZnO spheres were synthesized by changing weight percentage of Zn(NO_(3))_(2)·6 H_(2)O to tannic acid(TA).Moreover,highly active heterojunction mesoporous ZnO/Co_(3)O_(4)has been fabricated based on as-prepared ultra-small Co_(3)O_(4)nanocrystals(ca.3 nm)and mesoporous ZnO spheres by flexible impregnation technique.Profit from nano-size effect and synergistic effect of p-n heterojunction,mesoporous ZnO/Co_(3)O_(4)exhibited excellent acetone sensing performance with high selectivity,superior sensitivity and responsiveness.Typically,5 wt%Co_(3)O_(4)embedded mesoporous ZnO sphere showed prominent acetone response(ca.46 for 50 ppm),which was about 11.5 times higher than that in pure ZnO sensing device,and it was also endowed high cyclic stability.The nanocrystals embedded hybrid material is expected to be used as promising efficient material in the field of catalysis and gas sensing.展开更多
基金supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.52121004)National Natural Science Foundation of China(Nos.22276218 and 52022111)+1 种基金Major program Natural Science Foundation of Hunan Province of China(No.2021JC0001)Science and Technology Innovation Program of Hunan Province(No.2021RC3013).
文摘Dust particles emitted from smelters can be hazardous to ecosystems and humans,as they are often enriched in metallic compounds.Here,we combined multi-method mineralogical analysis with a sophisticated size sorting approach for copper smelting dust to study the nanosize-effect on heavy metal distribution,which has hitherto been underestimated.Three types of dust were collected from a copper flash smelter and then size-sorted using a Dekati low-pressure impactor.Results showed that all three samples could easily sort out nanoscale dust particles(<1μm,grades 10–2)and even those smaller than 100 nm(grades 5–2).Especially for electrostatic precipitators dust,the mass fraction of nanoscale dust(<1μm)could reach 10.71%.The presence of heavy metals(Pb,Zn,Cu,and As)and their mineral species in dust was examined at various particle sizes.It was discovered that different heavy metals are enriched on nanoparticles in specific sizes.In micron-sized particles,heavy metals are generally found in discrete phases(e.g.,CuSO_(4),PbSO_(4),and As_(2)O_(3)).In nanoscale particles,the dominant phase is Fe_(3)O_(4),while heavy metals are mostly found in lattice substitution(e.g.,CuFe_(2)O_(4)and ZnFe_(2)O_(4)).Two distinct nano-dust morphologies were found:One with irregular mesh or chain structures consisting of particles of a few nanometers,and the other with polygonal crystals in larger sizes of hundreds of nanometers.The enrichment of heavy metals in the latter morphology is more pronounced,possibly because lattice substitution of heavy metals is more likely to occur when polycrystalline particles are formed.
基金financially supported by the National Natural Science Foundation of China(Nos.21673048,21875044,52073064,22005058 and 22005057)National Key R&D Program of China(No.2018YFA0209401)+3 种基金Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)Program of Shanghai Academic Research Leader(No.19XD1420300)the state key laboratory of Transducer Technology of China(No.SKT1904)supporting project number(No.RSP-2020/155)。
文摘The rapid development of internet and internet of things brings new opportunities for the expansion of intelligent sensors,and acetone as a major disease detection indicator(i.e.,diabetes)making it become extremely important clinical indicator.Herein,uniform mesoporous ZnO spheres were successfully synthesized via novel formaldehyde-assisted metal-ligand crosslinking strategy.In order to adjust the pore structure of mesoporous ZnO,various mesoporous ZnO spheres were synthesized by changing weight percentage of Zn(NO_(3))_(2)·6 H_(2)O to tannic acid(TA).Moreover,highly active heterojunction mesoporous ZnO/Co_(3)O_(4)has been fabricated based on as-prepared ultra-small Co_(3)O_(4)nanocrystals(ca.3 nm)and mesoporous ZnO spheres by flexible impregnation technique.Profit from nano-size effect and synergistic effect of p-n heterojunction,mesoporous ZnO/Co_(3)O_(4)exhibited excellent acetone sensing performance with high selectivity,superior sensitivity and responsiveness.Typically,5 wt%Co_(3)O_(4)embedded mesoporous ZnO sphere showed prominent acetone response(ca.46 for 50 ppm),which was about 11.5 times higher than that in pure ZnO sensing device,and it was also endowed high cyclic stability.The nanocrystals embedded hybrid material is expected to be used as promising efficient material in the field of catalysis and gas sensing.
