Previous studies have reported associations of short-term exposure to different sources of ambient fine particulate matter(PM2.5)and increased mortality or hospitalizations for respiratory diseases.Few studies,however...Previous studies have reported associations of short-term exposure to different sources of ambient fine particulate matter(PM2.5)and increased mortality or hospitalizations for respiratory diseases.Few studies,however,have focused on the short-term effects of source-specific PM2.5 on emergency room visits(ERVs)of respiratory diseases.Source apportionment for PM2.5 was performed with Positive Matrix Factorization(PMF)and generalized additive model was applied to estimate associations between source-specific PM2.5 and respiratory disease ERVs.The association of PM2.5 and total respiratory ERVs was found on lag4(RR=1.011,95%CI:1.002,1.020)per interquartile range(76μg/m3)increase.We found PM2.5 to be significantly associated with asthma,bronchitis and chronic obstructive pulmonary disease(COPD)ERVs,with the strongest effects on lag5(RR=1.072,95%CI:1.024,1.119),lag4(RR=1.104,95%CI:1.032,1.176)and lag3(RR=1.091,95%CI:1.047,1.135),respectively.The estimated effects of PM2.5 changed little after adjusting for different air pollutants.Six primary PM2.5 sources were identified using PMF analysis,including dust/soil(6.7%),industry emission(4.5%),secondary aerosols(30.3%),metal processing(3.2%),coal combustion(37.5%)and traffic-related source(17.8%).Some of the sources were identified to have effects on ERVs of total respiratory diseases(dust/soil,secondary aerosols,metal processing,coal combustion and traffic-related source),bronchitis ERVs(dust/soil)and COPD ERVs(traffic-related source,industry emission and secondary aerosols).Different sources of PM2.5 contribute to increased risk of respiratory ERVs to different extents,which may provide potential implications for the decision making of air quality related policies,rational emission control and public health welfare.展开更多
Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the c...Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the complex synthesis procedures,limited active sites,and insufficient mechanistic understanding.Herein,a facile oxygen-tolerant synthesis strategy was developed,which utilizes the nitrogen-rich structure of g-C_(3)N_(4)to capture Fe single atoms from ammonium iron citrate,successfully constructing an efficient photocatalytic composite.The resulting Fe single-atom-modified g-C_(3)N_(4)catalyst exhibited highly improved light absorption,charge carrier separation,and a substantially enhanced rate of H_(2)production photocatalytically under visible light irradiation.Experimental results demonstrated that the optimal sample achieves a H_(2)production rate of 683μmol·h-1·g^(-1),representing a 425% enhancement compared to pristine g-C_(3)N_(4).This study presents a facile oxygen-tolerant approach for metal immobilization using metal-organic precursors,where the nitrogen-rich framework of g-C_(3)N_(4)effectively captures Fe atoms as singular site within the composite.The developed synthesis strategy provides new insights for designing high-performance single-atom photocatalytic materials,potentially advancing the application and development of photocatalysis.展开更多
Photocatalytic urea production from nitrogen(N_(2))and carbon dioxide(CO_(2))is a sustainable and ecofriendly alternative to the Bosch-Meiser route.However,it remains a significant challenge in developing highly effic...Photocatalytic urea production from nitrogen(N_(2))and carbon dioxide(CO_(2))is a sustainable and ecofriendly alternative to the Bosch-Meiser route.However,it remains a significant challenge in developing highly efficient photocatalysts for enhancing C-N coupling to high-yield urea synthesis.Herein,we propose a multi-site photocatalyst concept to address the concern of low yield by simultaneously improving photogenerated carrier separation and reactant activation.As a proof of concept,a well-defined multisite photocatalyst,Ru nanoparticles and Cu single atoms decorated CeO_(2)nanorods(Ru-Cu/CeO_(2)),is developed for efficient urea production.The incorporation of Ru and Cu sites is crucial not only to generate high-density photogenerated electrons,but also to facilitate N_(2)and CO_(2)adsorption and conversion.The in situ formed local nitrogen-rich area at Ru sites increases the encounter possibility with the carbon-containing species generated from Cu sites,substantially promoting C-N coupling.The Ru-Cu/CeO_(2)photocatalyst exhibits an impressive urea yield rate of 16.7μmol g^(-1)h^(-1),which ranks among the best performance reported to date.This work emphasizes the importance of multi-site catalyst design concept in guaranteeing rapid C-N coupling in photocatalytic urea synthesis and beyond.展开更多
Photocatalytic carbon dioxide(CO_(2))to carbon monoxide(CO)offers a promising way for both alleviating the greenhouse effect and meeting the industrial demand.Herein,we constructed a Co single-atom catalyst with inten...Photocatalytic carbon dioxide(CO_(2))to carbon monoxide(CO)offers a promising way for both alleviating the greenhouse effect and meeting the industrial demand.Herein,we constructed a Co single-atom catalyst with intentional low-coordination environment design on porous ZnO(denoted as Co1/ZnO).Impressively,Co1/ZnO exhibited a remarkable activity with a CO yield rate of 22.25 mmol·g^(-1)·h^(-1) and a selectivity of 80.2%for CO_(2) photoreduction reactions under visible light.The incorporation of single Co atoms provided an additional photo-generated electron transfer channel,which suppressed the carrier recombination of photocatalysts.Moreover,the unsaturated Co active sites were capable to adsorb CO_(2) molecule spontaneously,thus facilitating the activation of CO_(2) molecule during CO_(2) reduction course.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 81571130090, 91543112)the National Key Research and Development Program of China (Nos. 2016YFC0206506, 2017YFC0702700)+2 种基金the Ministry of Ecology and Environment: the research of national-level ecological and environmental planning (No. 14430019)the Peking University Health Science Center (No. BMU20160549)the National Young Thousand Talents Program of China
文摘Previous studies have reported associations of short-term exposure to different sources of ambient fine particulate matter(PM2.5)and increased mortality or hospitalizations for respiratory diseases.Few studies,however,have focused on the short-term effects of source-specific PM2.5 on emergency room visits(ERVs)of respiratory diseases.Source apportionment for PM2.5 was performed with Positive Matrix Factorization(PMF)and generalized additive model was applied to estimate associations between source-specific PM2.5 and respiratory disease ERVs.The association of PM2.5 and total respiratory ERVs was found on lag4(RR=1.011,95%CI:1.002,1.020)per interquartile range(76μg/m3)increase.We found PM2.5 to be significantly associated with asthma,bronchitis and chronic obstructive pulmonary disease(COPD)ERVs,with the strongest effects on lag5(RR=1.072,95%CI:1.024,1.119),lag4(RR=1.104,95%CI:1.032,1.176)and lag3(RR=1.091,95%CI:1.047,1.135),respectively.The estimated effects of PM2.5 changed little after adjusting for different air pollutants.Six primary PM2.5 sources were identified using PMF analysis,including dust/soil(6.7%),industry emission(4.5%),secondary aerosols(30.3%),metal processing(3.2%),coal combustion(37.5%)and traffic-related source(17.8%).Some of the sources were identified to have effects on ERVs of total respiratory diseases(dust/soil,secondary aerosols,metal processing,coal combustion and traffic-related source),bronchitis ERVs(dust/soil)and COPD ERVs(traffic-related source,industry emission and secondary aerosols).Different sources of PM2.5 contribute to increased risk of respiratory ERVs to different extents,which may provide potential implications for the decision making of air quality related policies,rational emission control and public health welfare.
基金financially supported by the National Natural Science Foundation of China(No.22272159)the Chinese Academy of Sciences(No.KFJ-XCZX-202304).
文摘Single-atom catalysts based on graphitic carbon nitride(g-C_(3)N_(4))show high potential for hydrogen production photocatalytically.However,it is still a challenge to develop single-atom-based g-C_(3)N_(4)due to the complex synthesis procedures,limited active sites,and insufficient mechanistic understanding.Herein,a facile oxygen-tolerant synthesis strategy was developed,which utilizes the nitrogen-rich structure of g-C_(3)N_(4)to capture Fe single atoms from ammonium iron citrate,successfully constructing an efficient photocatalytic composite.The resulting Fe single-atom-modified g-C_(3)N_(4)catalyst exhibited highly improved light absorption,charge carrier separation,and a substantially enhanced rate of H_(2)production photocatalytically under visible light irradiation.Experimental results demonstrated that the optimal sample achieves a H_(2)production rate of 683μmol·h-1·g^(-1),representing a 425% enhancement compared to pristine g-C_(3)N_(4).This study presents a facile oxygen-tolerant approach for metal immobilization using metal-organic precursors,where the nitrogen-rich framework of g-C_(3)N_(4)effectively captures Fe atoms as singular site within the composite.The developed synthesis strategy provides new insights for designing high-performance single-atom photocatalytic materials,potentially advancing the application and development of photocatalysis.
基金support by the National Natural Science Foundation of China(12222508,12475325,and 22209061)the Youth Innovation Promotion Association CAS(2020454)+2 种基金the National Key R&D Program of China(2019YFA0405601 and2023YFA1506304)the Fundamental Research Funds for the Universities of Inner Mongolia Autonomous Region(JY20250030)the Start-up Fund for Senior Talents in Jiangsu University(21JDG060)。
文摘Photocatalytic urea production from nitrogen(N_(2))and carbon dioxide(CO_(2))is a sustainable and ecofriendly alternative to the Bosch-Meiser route.However,it remains a significant challenge in developing highly efficient photocatalysts for enhancing C-N coupling to high-yield urea synthesis.Herein,we propose a multi-site photocatalyst concept to address the concern of low yield by simultaneously improving photogenerated carrier separation and reactant activation.As a proof of concept,a well-defined multisite photocatalyst,Ru nanoparticles and Cu single atoms decorated CeO_(2)nanorods(Ru-Cu/CeO_(2)),is developed for efficient urea production.The incorporation of Ru and Cu sites is crucial not only to generate high-density photogenerated electrons,but also to facilitate N_(2)and CO_(2)adsorption and conversion.The in situ formed local nitrogen-rich area at Ru sites increases the encounter possibility with the carbon-containing species generated from Cu sites,substantially promoting C-N coupling.The Ru-Cu/CeO_(2)photocatalyst exhibits an impressive urea yield rate of 16.7μmol g^(-1)h^(-1),which ranks among the best performance reported to date.This work emphasizes the importance of multi-site catalyst design concept in guaranteeing rapid C-N coupling in photocatalytic urea synthesis and beyond.
基金supported by the National Natural Science Foundation of China(Nos.1222508,U1932213)the Fundamental Research Funds for the Central Universities(No.WK2060000016)+1 种基金the USTC Research Funds of the Double First-Class Initiative(No.YD2310002005)the Youth Innovation Promotion Association CAS(No.2020454)。
文摘Photocatalytic carbon dioxide(CO_(2))to carbon monoxide(CO)offers a promising way for both alleviating the greenhouse effect and meeting the industrial demand.Herein,we constructed a Co single-atom catalyst with intentional low-coordination environment design on porous ZnO(denoted as Co1/ZnO).Impressively,Co1/ZnO exhibited a remarkable activity with a CO yield rate of 22.25 mmol·g^(-1)·h^(-1) and a selectivity of 80.2%for CO_(2) photoreduction reactions under visible light.The incorporation of single Co atoms provided an additional photo-generated electron transfer channel,which suppressed the carrier recombination of photocatalysts.Moreover,the unsaturated Co active sites were capable to adsorb CO_(2) molecule spontaneously,thus facilitating the activation of CO_(2) molecule during CO_(2) reduction course.
