The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants...The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.展开更多
Underwater superoleophobic-oleophilic chips were developed to achieve oil extracting from aqueous solution and oil-droplet con-densing to preset microwell.The double-hierarchical(extracting-condensing)enrichment strat...Underwater superoleophobic-oleophilic chips were developed to achieve oil extracting from aqueous solution and oil-droplet con-densing to preset microwell.The double-hierarchical(extracting-condensing)enrichment strategy drastically improves the sensitivi-ty for organic contaminants or components,whose signal amplification approaches 459.7 times that of primary solution and 25.9 times that of single condensing enrichment strategy.Low to femtomolar limit of detection(2.6×10^(-15)mol/L)sensitivity and 6 vari-ous aflatoxins or mildewed foods identification demonstrate the significance and promotion for environment monitoring,water pu-rification,and so on.展开更多
Aiming to the enormous requirement for the epidemic defense researches,we designed and constructed a spherical colloidal virus particle(CVP)to mimic nature virus in morphology,physical,chemical and biological characte...Aiming to the enormous requirement for the epidemic defense researches,we designed and constructed a spherical colloidal virus particle(CVP)to mimic nature virus in morphology,physical,chemical and biological characteristics,via coating spiky protein on col-loidal nanoparticles(CNPs)core with bulge hierarchical nanomorphology.The novel virus-like surface nanoparticles can easily be synthesized.The physical,chemical nature and the formation mechanism of the prepared CVPs were characterized and discussed.The synthesized CVPs are similar in size and envelope thickness to common natural viruses.It was demonstrated that the diameter of CVPs is about 238±12 nm,including an 8 nm thickness protein crown with bulges of 33 nm in average width.The CVPs with an isoelectric point of 4.5,meets the native virus property of negative charge under neutral condition.The protein crown enhances the roughness remarkably from 10 nm(CNPs)to 22 nm(CVPs)determined by atomic force microscopy.Thanks to the biomimetic rough morphology,the CVPs show greatly superior cellular uptake performance compared to CNPs,ovalbumin(OVA)and smoothed col-loidal particles(SCPs).The formation mechanism of protein crown with specific thickness can be attributed to the electrostatic in-teraction,protein's flexible structure and specific wettability.These results indicate that the as-prepared artificial virions mimic na-ture viruses in multi-dimension,in terms of size,surface rough morphology,surface negative charge and glycoprotein envelope composition.The synthetic colloidal virus particles pave a facile way toward engineering virus particles substitute for virus-related diseases prevention,diagnostics and cellular delivery vectors.展开更多
基金Project supported by the National Key Research and Development Plan(2021YFA1200201)the Natural Science Foundation of China(51872008)+1 种基金the"111"Project under the DB18015 grantBeijing Outstanding Young Scientists Projects(BJJWZYJH01201910005018)。
文摘The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous pollutants.It is proposed that the formation and diffusion of Ov originate from its outstanding reduction property.However,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still unknown.Herein,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)experiments.Ov is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained environment.Furthermore,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing temperature.Combined with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the subsurface.Furthermore,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces develope.These results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.
基金the National Natural Science Foundation of China(Nos.22090050,22090052,22176180,21874121,51803194,41807201,21874056,52003103,21974128)the National Key R&D Program of China(Nos.2016YFC1100502,2018YFE0206900)+2 种基金the Characteristic Innovation Projects of Guangdong Province for University(No.2018GKTSCX004)the Key Projects in Basic and Applied Research of Jjiangmen(Grant No.[2019]256)Zhejiang Provincial Natural Science Foundation of China under Grant No.LY20B050002 andNo.LD21B050001.
文摘Underwater superoleophobic-oleophilic chips were developed to achieve oil extracting from aqueous solution and oil-droplet con-densing to preset microwell.The double-hierarchical(extracting-condensing)enrichment strategy drastically improves the sensitivi-ty for organic contaminants or components,whose signal amplification approaches 459.7 times that of primary solution and 25.9 times that of single condensing enrichment strategy.Low to femtomolar limit of detection(2.6×10^(-15)mol/L)sensitivity and 6 vari-ous aflatoxins or mildewed foods identification demonstrate the significance and promotion for environment monitoring,water pu-rification,and so on.
基金supported by the National Natural ScienceFoundation of China(21874056,and 52003103 and 51873145)the National Key R&D Program of China(2016YFC1100502)+2 种基金the Zhejiang Provincial Natural Science Foundation of China(LY20B050002,LD21B050001)the Characteristic Innovation Pro-jects of Guangdong Province for University(2018GKTSCX004)the Key Projects in Basic and Applied Research of Jiangmen(GrantNo.[2019]256)。
文摘Aiming to the enormous requirement for the epidemic defense researches,we designed and constructed a spherical colloidal virus particle(CVP)to mimic nature virus in morphology,physical,chemical and biological characteristics,via coating spiky protein on col-loidal nanoparticles(CNPs)core with bulge hierarchical nanomorphology.The novel virus-like surface nanoparticles can easily be synthesized.The physical,chemical nature and the formation mechanism of the prepared CVPs were characterized and discussed.The synthesized CVPs are similar in size and envelope thickness to common natural viruses.It was demonstrated that the diameter of CVPs is about 238±12 nm,including an 8 nm thickness protein crown with bulges of 33 nm in average width.The CVPs with an isoelectric point of 4.5,meets the native virus property of negative charge under neutral condition.The protein crown enhances the roughness remarkably from 10 nm(CNPs)to 22 nm(CVPs)determined by atomic force microscopy.Thanks to the biomimetic rough morphology,the CVPs show greatly superior cellular uptake performance compared to CNPs,ovalbumin(OVA)and smoothed col-loidal particles(SCPs).The formation mechanism of protein crown with specific thickness can be attributed to the electrostatic in-teraction,protein's flexible structure and specific wettability.These results indicate that the as-prepared artificial virions mimic na-ture viruses in multi-dimension,in terms of size,surface rough morphology,surface negative charge and glycoprotein envelope composition.The synthetic colloidal virus particles pave a facile way toward engineering virus particles substitute for virus-related diseases prevention,diagnostics and cellular delivery vectors.
