The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alka...The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alkaline water.Precise control of the electronic structure by heteroatom doping has proven to be efficient for increasing catalytic activity.Nevertheless,both the structural characteristics and the underlying mechanism are not well understood,especially for doping with two different atoms,thus limiting the use of these catalysts.We report the production of phosphorus and nitrogen co-doped hollow carbon nanospheres(HCNs)by the copolymerization of pyrrole and aniline at a Triton X-100 micelle-interface,followed by doping with phytic acid and carbonization.The unique pore structure and defect-rich framework of the HCNs expose numerous active sites.Crucially,the combined effect of graphitic nitrogen and phosphorus-carbon bonds modulate the local electronic structure of adjacent C atoms and facilitates electron transfer.As a res-ult,the HCN carbonized at 1100°C exhibited superior HER activity and an outstanding stability(70 h at a current density of 10 mA cm^(−2))in alkaline water,because of the large number of graphitic nitrogen and phosphorus-carbon bonds.展开更多
A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres display...A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres displayed excellent fluorescence sensitivity and selectivity towards Hg^(2+)over other competing metal ions.A good linearity Stern-Volmer working plot(R2=0.9983)between the fluorescence intensity of multifunctional microspheres and the concentration of Hg^(2+)was constructed with a satisfactory detection limit of 2.3×10^(-8)mol·L^(-1).Their fluorescence response in the presence of Hg^(2+)is found to be almost reversible when treated by EDTA solution.Moreover,these pyrene-functionalized magnetic silica nanospheres can efficiently remove Hg^(2+)in aqueous solution and easily separated by appling an external magnetic field.These results indicate that functionalized core-shell magnetic silica microspheres are potentially promising materials for simultaneously detecting and removing environmental pollutants.展开更多
The toxic effects to microorganism induced by nanomaterials have received considerable attentions in the past decades [1]. Herein, two diverse nanomaterials i.e. multi-walled carbon nanotubes (MWCNTs) and mesoporous s...The toxic effects to microorganism induced by nanomaterials have received considerable attentions in the past decades [1]. Herein, two diverse nanomaterials i.e. multi-walled carbon nanotubes (MWCNTs) and mesoporous silica nanospheres (MSNs) were prepared to investigate their deleterious effects on Caenorhabditis. elegans (C. elegans)[2-3]. As shown in Figure 1A, histidine functionalized MWCNTs (his-MWCNTs) were in length of ~500 nm with outer diameter ~20 nm, while fluorescein isothiocyanate dyed MSNs (FITC-MSNs) were in an average diameter of ~70 nm (Figure 1B). Microscopic images display his-MWCNTs having been ingested into intestine of C. elegans after co-incubation for 2 h, as arrowed in Figure 1C and 1E. In contrast, no MSNs were observed to be ingested after co-incubating in the same liquid medium. However, fluorescence microscopic images (Figure 1D and 1F) demonstrate that FITC-MSNs could be ingested by C. elegans after co-incubation for 24 h or longer time via seeding Kingagar plates with FITC-MSNs.展开更多
基金financially supported by the project of the National Natural Science Foundation of China(52322203)the Key Research and Development Program of Shaanxi Province(2024GHZDXM-21)。
文摘The design of cost-effective and efficient metal-free carbon-based catalysts for the hydrogen evolution reaction(HER)is of great significance for increasing the production of clean hydrogen by the electrolysis of alkaline water.Precise control of the electronic structure by heteroatom doping has proven to be efficient for increasing catalytic activity.Nevertheless,both the structural characteristics and the underlying mechanism are not well understood,especially for doping with two different atoms,thus limiting the use of these catalysts.We report the production of phosphorus and nitrogen co-doped hollow carbon nanospheres(HCNs)by the copolymerization of pyrrole and aniline at a Triton X-100 micelle-interface,followed by doping with phytic acid and carbonization.The unique pore structure and defect-rich framework of the HCNs expose numerous active sites.Crucially,the combined effect of graphitic nitrogen and phosphorus-carbon bonds modulate the local electronic structure of adjacent C atoms and facilitates electron transfer.As a res-ult,the HCN carbonized at 1100°C exhibited superior HER activity and an outstanding stability(70 h at a current density of 10 mA cm^(−2))in alkaline water,because of the large number of graphitic nitrogen and phosphorus-carbon bonds.
文摘A recyclable mercury(Ⅱ)optical sensor based on pyrene-functionalized core-shell magnetic silica nanosphereswas developed and demonstrated by sol-gel grafting reaction.The obtained multifunctional microspheres displayed excellent fluorescence sensitivity and selectivity towards Hg^(2+)over other competing metal ions.A good linearity Stern-Volmer working plot(R2=0.9983)between the fluorescence intensity of multifunctional microspheres and the concentration of Hg^(2+)was constructed with a satisfactory detection limit of 2.3×10^(-8)mol·L^(-1).Their fluorescence response in the presence of Hg^(2+)is found to be almost reversible when treated by EDTA solution.Moreover,these pyrene-functionalized magnetic silica nanospheres can efficiently remove Hg^(2+)in aqueous solution and easily separated by appling an external magnetic field.These results indicate that functionalized core-shell magnetic silica microspheres are potentially promising materials for simultaneously detecting and removing environmental pollutants.
文摘The toxic effects to microorganism induced by nanomaterials have received considerable attentions in the past decades [1]. Herein, two diverse nanomaterials i.e. multi-walled carbon nanotubes (MWCNTs) and mesoporous silica nanospheres (MSNs) were prepared to investigate their deleterious effects on Caenorhabditis. elegans (C. elegans)[2-3]. As shown in Figure 1A, histidine functionalized MWCNTs (his-MWCNTs) were in length of ~500 nm with outer diameter ~20 nm, while fluorescein isothiocyanate dyed MSNs (FITC-MSNs) were in an average diameter of ~70 nm (Figure 1B). Microscopic images display his-MWCNTs having been ingested into intestine of C. elegans after co-incubation for 2 h, as arrowed in Figure 1C and 1E. In contrast, no MSNs were observed to be ingested after co-incubating in the same liquid medium. However, fluorescence microscopic images (Figure 1D and 1F) demonstrate that FITC-MSNs could be ingested by C. elegans after co-incubation for 24 h or longer time via seeding Kingagar plates with FITC-MSNs.
