In Fenton-like reactions,high-valent cobalt-oxo(Co^(IV)=O)has attracted increasing interests due to high redox potential,long lifetime,and anti-interference properties,but its generation is hindered by the electron re...In Fenton-like reactions,high-valent cobalt-oxo(Co^(IV)=O)has attracted increasing interests due to high redox potential,long lifetime,and anti-interference properties,but its generation is hindered by the electron repulsion between the electron rich oxo-and cobalt centers.Here,we demonstrate Co^(IV)=O generation from peroxymonosulfate(PMS)activation over cobalt single-atom catalysts(Co-SACs)using in-situ Co K-edge X-ray absorption spectra,and discern that Co^(IV)=O generation is dependent on the support work-function(WF)due to the strong electronic metal-support interaction(EMSI).Supports with a high WF value like anatase-TiO_(2)facilitate the binding of PMS-terminal oxo-ligand to Co sites by extracting Cod electrons,thus decreasing the generation barrier for the critical intermediate(Co-OOSO_(3)^(2-)).The Co atoms anchored on anatase-TiO_(2)(Co-TiO_(2))exhibited enhanced Co^(IV)=O generation and superior activity for sulfamethoxazole(SMX)degradation during PMS activation.The normalized steady-state concentration of Co^(IV)=O in Co-TiO_(2)/PMS system was three orders of magnitude higher than that of free radicals,and 1.3-to 11-fold higher than that generated in other Co-SACs/PMS systems.Co-TiO_(2)/PMS sustained efficient removal of SMX with minimal Co^(2+)leaching under continuous flow operation,suggesting its attractive water purification potential.Overall,these results underscore the significance of support selection for enhanced generation of high-valent metal-oxo species and efficient PMS activation in supported metal SACs.展开更多
The concentration and molecular composition of soil organic matter(SOM)are important factors in mitigation against climate change as well as providing other ecosystem services.Our quantitative understanding of how lan...The concentration and molecular composition of soil organic matter(SOM)are important factors in mitigation against climate change as well as providing other ecosystem services.Our quantitative understanding of how land use influences SOM molecular composition and associated turnover dynamics is limited,which underscores the need for high-throughput analytical approaches and molecular marker signatures to clarify this etiology.Combining a high-throughput untargeted mass spectrometry screening and molecular markers,we show that forest,farmland and urban land uses result in distinct molecular signatures of SOM in the Lake Chaohu Basin.Molecular markers indicate that forest SOM has abundant carbon contents from vegetation and condensed organic carbon,leading to high soil organic carbon(SOC)concentration.Farmland SOM has moderate carbon contents from vegetation,and limited content of condensed organic carbon,with SOC significantly lower than that of forest soils.Urban SOM has high abundance of condensed organic carbon markers due to anthropogenic activities but relatively low in markers from vegetation.Consistently,urban soils have the highest black carbon/SOC ratio among these land uses.Overall,our results suggested that the molecular signature of SOM varies significantly with land use in the Lake Chaohu Basin,influencing carbon dynamics.Our strategy of molecular fingerprinting and marker discovery is expected to enlighten further research on SOM molecular signatures and cycling dynamics.展开更多
基金supported by the National Natural Science Foundation of China(22376138 and 52070128)the National Key R&D Program of China(2023YFC3708005)National Science Foundation Engineering Research Centers on Nanotechnology-Enabled Water Treatment(EEC-1449500)。
文摘In Fenton-like reactions,high-valent cobalt-oxo(Co^(IV)=O)has attracted increasing interests due to high redox potential,long lifetime,and anti-interference properties,but its generation is hindered by the electron repulsion between the electron rich oxo-and cobalt centers.Here,we demonstrate Co^(IV)=O generation from peroxymonosulfate(PMS)activation over cobalt single-atom catalysts(Co-SACs)using in-situ Co K-edge X-ray absorption spectra,and discern that Co^(IV)=O generation is dependent on the support work-function(WF)due to the strong electronic metal-support interaction(EMSI).Supports with a high WF value like anatase-TiO_(2)facilitate the binding of PMS-terminal oxo-ligand to Co sites by extracting Cod electrons,thus decreasing the generation barrier for the critical intermediate(Co-OOSO_(3)^(2-)).The Co atoms anchored on anatase-TiO_(2)(Co-TiO_(2))exhibited enhanced Co^(IV)=O generation and superior activity for sulfamethoxazole(SMX)degradation during PMS activation.The normalized steady-state concentration of Co^(IV)=O in Co-TiO_(2)/PMS system was three orders of magnitude higher than that of free radicals,and 1.3-to 11-fold higher than that generated in other Co-SACs/PMS systems.Co-TiO_(2)/PMS sustained efficient removal of SMX with minimal Co^(2+)leaching under continuous flow operation,suggesting its attractive water purification potential.Overall,these results underscore the significance of support selection for enhanced generation of high-valent metal-oxo species and efficient PMS activation in supported metal SACs.
基金supported by the National Key R&D Program of China(grant nos.2019YFC1804201,2020YFC1807002)China Postdoctoral Science Foundation(grant no.2021M701670)+1 种基金the National Natural Science Foundation of China(grant no.21876075)Jiangsu Planned Projects for Postdoctoral Research Funds(grant no.2021K357C).
文摘The concentration and molecular composition of soil organic matter(SOM)are important factors in mitigation against climate change as well as providing other ecosystem services.Our quantitative understanding of how land use influences SOM molecular composition and associated turnover dynamics is limited,which underscores the need for high-throughput analytical approaches and molecular marker signatures to clarify this etiology.Combining a high-throughput untargeted mass spectrometry screening and molecular markers,we show that forest,farmland and urban land uses result in distinct molecular signatures of SOM in the Lake Chaohu Basin.Molecular markers indicate that forest SOM has abundant carbon contents from vegetation and condensed organic carbon,leading to high soil organic carbon(SOC)concentration.Farmland SOM has moderate carbon contents from vegetation,and limited content of condensed organic carbon,with SOC significantly lower than that of forest soils.Urban SOM has high abundance of condensed organic carbon markers due to anthropogenic activities but relatively low in markers from vegetation.Consistently,urban soils have the highest black carbon/SOC ratio among these land uses.Overall,our results suggested that the molecular signature of SOM varies significantly with land use in the Lake Chaohu Basin,influencing carbon dynamics.Our strategy of molecular fingerprinting and marker discovery is expected to enlighten further research on SOM molecular signatures and cycling dynamics.
