Label-free 3D tomography has attracted growing attention in biological imaging due to its inherent resistance to phototoxicity and concise system configuration.Among existing techniques,Fourier ptychographic tomograph...Label-free 3D tomography has attracted growing attention in biological imaging due to its inherent resistance to phototoxicity and concise system configuration.Among existing techniques,Fourier ptychographic tomography(FPT)stands out for high-resolution refractive index(RI)reconstruction from noninterferometric measurements,avoiding coherent noise and phase instability-key limitations of optical diffraction tomography.However,conventional FPT suffers from significant artifacts and high computational demands,especially for multiscattering samples and long-term observation.Here,we introduce physicsinformed aberration-corrected meta neural representation(PAMR),an advanced self-supervised framework that integrates neural representation with physics prior,meta-learning optimization,and adaptive aberration correction.Simulations and experiments show that PAMR produces high-fidelity 3D reconstructions with reduced artifacts and strong optical section ability,achieving 137 and 550 nm resolution for lateral and axial,respectively.Moreover,PAMR exhibits superior sparse-view robustness,sustaining high-quality with 75%view reduction.Through the meta-learning strategy,the reconstruction speed of dynamic volumes could be increased by 10 times.Applications include 3D RI imaging of multiscattering C.elegans and long-term 3D observation of HeLa cells,showing detailed organelle structures and interactions.As a generalizable approach combining computational efficiency with physical accuracy,PAMR provides an advanced algorithm for label-free 3D microscopy,with broad applicability across biomedical research.展开更多
Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis efficiency.This study uses the advanta...Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis efficiency.This study uses the advantages of SPR in metallic Bi and artificial defects to cooperatively enhance the photocatalytic performance of BiOI.The catalysts were prepared by partial reduction of BiOI to form Bi@defective BiOI,which showed highly enhanced visible photocatalytic activity for NOx removal.The effects of reductant quantity on the photocatalytic performance of Bi@defective BiOI were investigated.The as-prepared photocatalyst(Bi/BiOI-2)using 2 mmol of reductant NaBH4 showed the most efficient visible light photocatalytic activity.This enhanced activity can be ascribed to the synergistic effects of metallic Bi and oxygen vacancies.The electrons from the valence band tend to accumulate at vacancy states;therefore,the increased charge density would cause the adsorbed oxygen to transform more easily into superoxide radicals and,further,into hydroxyl radicals.These radicals are the main active species that oxidize NO into final products.The SPR effect of elemental Bi enables the improvement of visible light absorption efficiency and the promotion of charge carrier separation,which are crucial factors in boosting photocatalysis.NO adsorption and reaction processes on Bi/BiOI-2 were dynamically monitored by in situ infrared spectroscopy(FT-IR).The Bi/BiOI photocatalysis mechanism co-mediated by elemental Bi and oxygen vacancies was proposed based on the analysis of intermediate products and DFT calculations.This present work could provide new insights into the design of high-performance photocatalysts and understanding of the photocatalysis reaction mechanism for air-purification applications.展开更多
The simultaneous integration of heteroatom doping and surface plasmon resonance(SPR) modulation on semiconductor photocatalysts could be capable of improving visible light utilization and charge separation, achieving ...The simultaneous integration of heteroatom doping and surface plasmon resonance(SPR) modulation on semiconductor photocatalysts could be capable of improving visible light utilization and charge separation, achieving better solar light conversion and photocatalysis efficiency. For this purpose, we have designed a novel Bi quantum dots(QDs) implanted C-doped BiOCl photocatalyst(C/BOC/B) for NOx removal. The feasibility was firstly evaluated through density functional theory(DFT) calculations methods, which indicates that the enhanced photocatalytic performance could be expected owing to the synergistic effects of doped C heteroatoms and loaded Bi QDs. Then, the C/BOC/B was synthesized via a facile hydrothermal method and exhibited efficient and stable visible light photocatalytic NO removal. The results found that the doped C atoms can serve as electron guides to induce oriented charge transfer from Bi QDs to BiOCl, while the Bi QDs can act as light-capture and electron-donating sites. The reaction pathway and mechanism for NO conversion was unveiled by in situ Fourier-transform infrared spectroscopy combined with DFT calculation. The enhanced adsorption of reactants and intermediates could promote the overall reaction efficiency and selectivity in photocatalytic NO conversion. This work could provide a new perspective on the mechanistic understanding of the synergistic effects toward non-metal doping and SPR effects in semiconductor photocatalysts, and this presented technique could be extended for other semiconductor materials.展开更多
In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the wat...In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the water/ethylene glycol ratio.Although the role of OVs in photocatalysis has been investigated,the underlying mechanisms of charge transfer and reactant activation remain unknown.To unravel the effect of OVs on the reactant activation and photocatalytic NO oxidation process,in situ diffuse reflectance infrared Fourier transform spectroscopy,so‐called DRIFTS,and theoretical calculations were performed and their results combined.The photocatalytic efficiency of the as‐prepared BiOBr was significantly increased by increasing the amount of OVs.The oxygen vacancies had several effects on the photocatalysts,including the introduction of intermediate energy levels that enhanced light absorption,promoted electron transfer,acted as active sites for catalytic reaction and the activation of oxygen molecules,and facilitated the conversion of the intermediate products to the final product,thus increasing the overall visible light photocatalysis efficiency.The present work provides new insights into the understanding of the role of OVs in photocatalysts and the mechanism of photocatalytic NO oxidation.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3401100)the National Natural Science Foundation of China(Grant Nos.22534002,T2225014,62405099,32401253,and 62375095)+2 种基金the China Postdoctoral Science Foundation(Grant Nos.2024M750994 and 2024M761020)the Postdoctoral Project of Hubei Province(Grant Nos.2024HBBHCXA015 and 2024HBBHCXA013)the Key Research and Development Project of Hubei Province(Grant Nos.2024BCB011 and 2024BCB112).
文摘Label-free 3D tomography has attracted growing attention in biological imaging due to its inherent resistance to phototoxicity and concise system configuration.Among existing techniques,Fourier ptychographic tomography(FPT)stands out for high-resolution refractive index(RI)reconstruction from noninterferometric measurements,avoiding coherent noise and phase instability-key limitations of optical diffraction tomography.However,conventional FPT suffers from significant artifacts and high computational demands,especially for multiscattering samples and long-term observation.Here,we introduce physicsinformed aberration-corrected meta neural representation(PAMR),an advanced self-supervised framework that integrates neural representation with physics prior,meta-learning optimization,and adaptive aberration correction.Simulations and experiments show that PAMR produces high-fidelity 3D reconstructions with reduced artifacts and strong optical section ability,achieving 137 and 550 nm resolution for lateral and axial,respectively.Moreover,PAMR exhibits superior sparse-view robustness,sustaining high-quality with 75%view reduction.Through the meta-learning strategy,the reconstruction speed of dynamic volumes could be increased by 10 times.Applications include 3D RI imaging of multiscattering C.elegans and long-term 3D observation of HeLa cells,showing detailed organelle structures and interactions.As a generalizable approach combining computational efficiency with physical accuracy,PAMR provides an advanced algorithm for label-free 3D microscopy,with broad applicability across biomedical research.
基金supported by the National Natural Science Foundation of China(21501016,21777011 and 21822601)the National Key R&D Program of China(2016YFC02047)+2 种基金the Innovative Research Team of Chongqing(CXTDG201602014)the Key Natural Science Foundation of Chongqing(cstc2017jcyj BX0052)the National Ten Thousand Talent Program of China~~
文摘Surface plasmon resonance(SPR)of metals may provide a way to improve light absorption and utilization of semiconductors,achieving better solar light conversion and photocatalysis efficiency.This study uses the advantages of SPR in metallic Bi and artificial defects to cooperatively enhance the photocatalytic performance of BiOI.The catalysts were prepared by partial reduction of BiOI to form Bi@defective BiOI,which showed highly enhanced visible photocatalytic activity for NOx removal.The effects of reductant quantity on the photocatalytic performance of Bi@defective BiOI were investigated.The as-prepared photocatalyst(Bi/BiOI-2)using 2 mmol of reductant NaBH4 showed the most efficient visible light photocatalytic activity.This enhanced activity can be ascribed to the synergistic effects of metallic Bi and oxygen vacancies.The electrons from the valence band tend to accumulate at vacancy states;therefore,the increased charge density would cause the adsorbed oxygen to transform more easily into superoxide radicals and,further,into hydroxyl radicals.These radicals are the main active species that oxidize NO into final products.The SPR effect of elemental Bi enables the improvement of visible light absorption efficiency and the promotion of charge carrier separation,which are crucial factors in boosting photocatalysis.NO adsorption and reaction processes on Bi/BiOI-2 were dynamically monitored by in situ infrared spectroscopy(FT-IR).The Bi/BiOI photocatalysis mechanism co-mediated by elemental Bi and oxygen vacancies was proposed based on the analysis of intermediate products and DFT calculations.This present work could provide new insights into the design of high-performance photocatalysts and understanding of the photocatalysis reaction mechanism for air-purification applications.
文摘The simultaneous integration of heteroatom doping and surface plasmon resonance(SPR) modulation on semiconductor photocatalysts could be capable of improving visible light utilization and charge separation, achieving better solar light conversion and photocatalysis efficiency. For this purpose, we have designed a novel Bi quantum dots(QDs) implanted C-doped BiOCl photocatalyst(C/BOC/B) for NOx removal. The feasibility was firstly evaluated through density functional theory(DFT) calculations methods, which indicates that the enhanced photocatalytic performance could be expected owing to the synergistic effects of doped C heteroatoms and loaded Bi QDs. Then, the C/BOC/B was synthesized via a facile hydrothermal method and exhibited efficient and stable visible light photocatalytic NO removal. The results found that the doped C atoms can serve as electron guides to induce oriented charge transfer from Bi QDs to BiOCl, while the Bi QDs can act as light-capture and electron-donating sites. The reaction pathway and mechanism for NO conversion was unveiled by in situ Fourier-transform infrared spectroscopy combined with DFT calculation. The enhanced adsorption of reactants and intermediates could promote the overall reaction efficiency and selectivity in photocatalytic NO conversion. This work could provide a new perspective on the mechanistic understanding of the synergistic effects toward non-metal doping and SPR effects in semiconductor photocatalysts, and this presented technique could be extended for other semiconductor materials.
文摘In this work,a series of BiOBr nanoplates with oxygen vacancies(OVs)were synthesized by a solvothermal method using a water/ethylene glycol solution.The number of OVs and facets of BiOBr were tuned by changing the water/ethylene glycol ratio.Although the role of OVs in photocatalysis has been investigated,the underlying mechanisms of charge transfer and reactant activation remain unknown.To unravel the effect of OVs on the reactant activation and photocatalytic NO oxidation process,in situ diffuse reflectance infrared Fourier transform spectroscopy,so‐called DRIFTS,and theoretical calculations were performed and their results combined.The photocatalytic efficiency of the as‐prepared BiOBr was significantly increased by increasing the amount of OVs.The oxygen vacancies had several effects on the photocatalysts,including the introduction of intermediate energy levels that enhanced light absorption,promoted electron transfer,acted as active sites for catalytic reaction and the activation of oxygen molecules,and facilitated the conversion of the intermediate products to the final product,thus increasing the overall visible light photocatalysis efficiency.The present work provides new insights into the understanding of the role of OVs in photocatalysts and the mechanism of photocatalytic NO oxidation.
