Photocatalytic activation of peroxymonosulfate (PMS) has garnered a lot of interest in the field of wastewater treatment. Herein, a plasmonic Ag nanoparticles decorated MIL-101(Fe) hybrid was synthesized through a pho...Photocatalytic activation of peroxymonosulfate (PMS) has garnered a lot of interest in the field of wastewater treatment. Herein, a plasmonic Ag nanoparticles decorated MIL-101(Fe) hybrid was synthesized through a photodeposition process. Upon light irradiation, the Ag/MIL-101(Fe) exhibit reinforced photocatalytic activities for elimination of bisphenol A (BPA) with PMS. The optimized 2.0% Ag/MIL-101(Fe) composite presented the highest photocatalytic activity with kinetic constant k of 0.102 min-1, which was about 10-fold of the pristine MIL-101(Fe). Loading of plasmonic Ag into MIL-101(Fe) boosts photoinduced carrier separation and accelerates PMS activation to generate strong oxidative radicals. Photoelectrochemical tests and multiple spectroscopic studies confirmed the promoted charge carrier separation and transfer capability of Ag/MIL-101(Fe). Combining the results of radical trapping experiments and electron spin resonance (ESR), the formed SO4·-, ·OH, ·O2- and 1O2 had a significant role in the photocatalytic process. According to intermediate study, the degradation pathway was studied, and the possible mechanism was proposed.展开更多
Adsorption of the hydrophobic organic compounds （HOCs） trichloroethylene （TCE）, 1,3-dichlorobenzene （DCB）, 1,3-dirdtrobenzene （DNB） and y-hexachlorocyclohexane （HCH） on five different carbonaceous materials ...Adsorption of the hydrophobic organic compounds （HOCs） trichloroethylene （TCE）, 1,3-dichlorobenzene （DCB）, 1,3-dirdtrobenzene （DNB） and y-hexachlorocyclohexane （HCH） on five different carbonaceous materials was compared. The adsorbents included three polymer-based activated carbons, one coal-based activated carbon （F400） and multiwalled carbon nanotubes （MWNT）. The polymer- based activated carbons were prepared using KOH activation from waste polymers： polyvinyl chloride （PVC）, polyethyleneterephthalate （PET） and tire rubber （TR）. Compared with F400 and MWNT, activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs, attributed to their extremely large hydrophobic surface area （2700 m2/g） and highly mesoporous structures. Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect. In contrast, due to the molecular sieving effect, their adsorption on HCH was lower. MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.展开更多
The incomplete combustion of biomass and fossil fuels results in the formation of not only black carbon(BC)but also black nitrogen(BN),the dissolved fractions of which(i.e.,DBC and DBN)are important components of diss...The incomplete combustion of biomass and fossil fuels results in the formation of not only black carbon(BC)but also black nitrogen(BN),the dissolved fractions of which(i.e.,DBC and DBN)are important components of dissolved organic matter pool.Relative to DBC,the activity and reactivity of DBN are much less understood.Here,we investigated the catalytic effect of DBN derived from N-enriched biomass in the abiotic transformation of chlorophenols by sulfides.The medium-temperature DBN(450°C)exhibited 13-144%higher catalytic efficiency than other DBN samples and 9.3 times higher than its DBC counterpart.Both electron paramagnetic resonance spectra and fluorescent probe technique indicated that the attached sulfides contributed to the formation of reactive oxygen species(ROS)as the“primary”radicals by favoring electron transfer from DBN to chemisorbed oxygen,and then the generated ROS reacted with N-oxides in DBN to form reactive nitrogen species(RNS)as the“secondary”radicals.The contribution of RNS to the decay of 2-chlorophenol by DBN450 was up to 72%,much higher than that of ROS and non-radical mechanism.These findings suggest that the catalytic effect of DBN is distinct but no less significant than that of DBC to the abiotic transformation of micropollutants in water/soil systems.展开更多
A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily a...A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily accessible 4,4-di-tert-butyl bipyridine(dtbpy),acting as a halogen bonding acceptor,shifted the reduction potential of C—Cl bonds positively by 110 mV.The decreased operating potential leads to a wide substrate scope and excellent functional group compatibility.A diverse array of terminal and internal alkenes such as(hetero)aryl olefins,unactive aliphatic olefins,and natural products and drugs-derived olefins were well compatible.展开更多
Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dua...Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dual activation strategy enables rapid access to densely functionalized 2-alkylidene-tetrahydrofurans with exclusive Z-selectivities,which are challenging to be synthesized by other methods.4,4′-Di-tert-butyl-2,2′-bipyridine(dtbbpy)showed an unprecedented reactivity as a XB acceptor to activate C-Cl bond by shifting its reduction potential positively by 220 m V.Distinctly different from previous electroreductions of C-Cl bonds relying upon high electrode potentials or matched redox properties between mediators and organochlorides,the XB activator employed herein has no limit on the abovementioned redox property matching but can lower the applied electrode potentials.The decreased operating potential allows broad functional group tolerance,which was highlighted by the late-stage functionalization of 11 examples of drugs and natural products-derived alkenes.展开更多
Nano-black carbon(BC)is one of the most active fractions in the pyrogenic carbonaceous matter continuum.The majority of recent studies mainly focus on the role of nano-BC in the global carbon cycle.However,based on li...Nano-black carbon(BC)is one of the most active fractions in the pyrogenic carbonaceous matter continuum.The majority of recent studies mainly focus on the role of nano-BC in the global carbon cycle.However,based on literature and our recent studies,we suggest that nano-BC may also serve as a super suspending agent,carrier,and redox mediator for sorbates during its migration from terrestrial to water bodies due to its unique properties such as high colloidal stability,strong sorption capacity,and high surface reactivity.The full implications of nano-BC in water/soil environments are far more than we expected.Thus,we call for more detailed investigations on the activity and reactivity of nano-BC in water/soil environments.展开更多
The electrochemical utilization of electron-deficient methylarenes for radical-radical cross-couplings remains very rare.Enabled by an umpolung strategy,the unprecedented electrochemical cross-coupling of electron-def...The electrochemical utilization of electron-deficient methylarenes for radical-radical cross-couplings remains very rare.Enabled by an umpolung strategy,the unprecedented electrochemical cross-coupling of electron-deficient methylarenes with aldehydes was developed.The paired electrolysis simultaneously generated electron-deficient benzylic radicals and ketyl radicals at both electrodes,which then underwent radical recombination,governed by polarity matching and persistent-radical effect(PRE)to afford functionalized alcohols that are not easily accessible by other methods.This protocol features catalystand external redox agent-free conditions and a formal 100%atom economy.Mechanistic studies support the radical-radical cross-coupling pathway.展开更多
基金Natural Science Foundation of Hebei Province, China (No. B2020202044)the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, China (No. KLIEEE-21-04).
文摘Photocatalytic activation of peroxymonosulfate (PMS) has garnered a lot of interest in the field of wastewater treatment. Herein, a plasmonic Ag nanoparticles decorated MIL-101(Fe) hybrid was synthesized through a photodeposition process. Upon light irradiation, the Ag/MIL-101(Fe) exhibit reinforced photocatalytic activities for elimination of bisphenol A (BPA) with PMS. The optimized 2.0% Ag/MIL-101(Fe) composite presented the highest photocatalytic activity with kinetic constant k of 0.102 min-1, which was about 10-fold of the pristine MIL-101(Fe). Loading of plasmonic Ag into MIL-101(Fe) boosts photoinduced carrier separation and accelerates PMS activation to generate strong oxidative radicals. Photoelectrochemical tests and multiple spectroscopic studies confirmed the promoted charge carrier separation and transfer capability of Ag/MIL-101(Fe). Combining the results of radical trapping experiments and electron spin resonance (ESR), the formed SO4·-, ·OH, ·O2- and 1O2 had a significant role in the photocatalytic process. According to intermediate study, the degradation pathway was studied, and the possible mechanism was proposed.
基金supported by the Tianjin Municipal Science and Technology Commission (No. 08ZCGHHZ01000)the Ministry of Education of China (No. 708020)+1 种基金the Ministry of Science and Technology of China (No. 2008ZX08526-003,2009DFA91910)the New Century Talent program,and the China-US Center for Environmental Remediation and Sustainable Development
文摘Adsorption of the hydrophobic organic compounds （HOCs） trichloroethylene （TCE）, 1,3-dichlorobenzene （DCB）, 1,3-dirdtrobenzene （DNB） and y-hexachlorocyclohexane （HCH） on five different carbonaceous materials was compared. The adsorbents included three polymer-based activated carbons, one coal-based activated carbon （F400） and multiwalled carbon nanotubes （MWNT）. The polymer- based activated carbons were prepared using KOH activation from waste polymers： polyvinyl chloride （PVC）, polyethyleneterephthalate （PET） and tire rubber （TR）. Compared with F400 and MWNT, activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs, attributed to their extremely large hydrophobic surface area （2700 m2/g） and highly mesoporous structures. Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect. In contrast, due to the molecular sieving effect, their adsorption on HCH was lower. MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.
基金supported by the National Natural Science Foundation of China(41977278)the Natural Science Foundation of Hebei province(D2022202004)+1 种基金the Natural Science Foundation of Tianjin(23JCYBJC00940)the Central Government-guided Local Science and Technology Development Foundation of Hebei province(236Z7301G).
文摘The incomplete combustion of biomass and fossil fuels results in the formation of not only black carbon(BC)but also black nitrogen(BN),the dissolved fractions of which(i.e.,DBC and DBN)are important components of dissolved organic matter pool.Relative to DBC,the activity and reactivity of DBN are much less understood.Here,we investigated the catalytic effect of DBN derived from N-enriched biomass in the abiotic transformation of chlorophenols by sulfides.The medium-temperature DBN(450°C)exhibited 13-144%higher catalytic efficiency than other DBN samples and 9.3 times higher than its DBC counterpart.Both electron paramagnetic resonance spectra and fluorescent probe technique indicated that the attached sulfides contributed to the formation of reactive oxygen species(ROS)as the“primary”radicals by favoring electron transfer from DBN to chemisorbed oxygen,and then the generated ROS reacted with N-oxides in DBN to form reactive nitrogen species(RNS)as the“secondary”radicals.The contribution of RNS to the decay of 2-chlorophenol by DBN450 was up to 72%,much higher than that of ROS and non-radical mechanism.These findings suggest that the catalytic effect of DBN is distinct but no less significant than that of DBC to the abiotic transformation of micropollutants in water/soil systems.
基金the National Natural Science Foundation of China(21871019,21901263,22171015)Beijing Municipal Education Committee Project(KZ202110005003,KM202110005006)Beijing Natural Science Foundation(2222003).
文摘A new electrochemical strategy for the atom transfer radical addition(ATRA)of polychloroalkanes across olefins has been realized by the synergism of paired electrolysis and halogen bonding activation.Notably,readily accessible 4,4-di-tert-butyl bipyridine(dtbpy),acting as a halogen bonding acceptor,shifted the reduction potential of C—Cl bonds positively by 110 mV.The decreased operating potential leads to a wide substrate scope and excellent functional group compatibility.A diverse array of terminal and internal alkenes such as(hetero)aryl olefins,unactive aliphatic olefins,and natural products and drugs-derived olefins were well compatible.
基金supported by the National Natural Science Foundation of China(21871019,22171015)Beijing Municipal Education Committee Project(KZ202110005003,KM202110005006)Beijing Natural Science Foundation(2222003)。
文摘Reported herein is the design of a new catalytic paradigm by synergistically combining sequential paired electrosynthesis with halogen-bonding(XB)activation for the cyclization of organochlorides with olefins.This dual activation strategy enables rapid access to densely functionalized 2-alkylidene-tetrahydrofurans with exclusive Z-selectivities,which are challenging to be synthesized by other methods.4,4′-Di-tert-butyl-2,2′-bipyridine(dtbbpy)showed an unprecedented reactivity as a XB acceptor to activate C-Cl bond by shifting its reduction potential positively by 220 m V.Distinctly different from previous electroreductions of C-Cl bonds relying upon high electrode potentials or matched redox properties between mediators and organochlorides,the XB activator employed herein has no limit on the abovementioned redox property matching but can lower the applied electrode potentials.The decreased operating potential allows broad functional group tolerance,which was highlighted by the late-stage functionalization of 11 examples of drugs and natural products-derived alkenes.
基金The work was supported by the National Natural Science Foundation of China(41977278 and 41573127)the Fundamental Research Funds for the Central Universities(JUSRP22015).BX acknowledges the UMass Amherst Conti Faculty Fellowship.
文摘Nano-black carbon(BC)is one of the most active fractions in the pyrogenic carbonaceous matter continuum.The majority of recent studies mainly focus on the role of nano-BC in the global carbon cycle.However,based on literature and our recent studies,we suggest that nano-BC may also serve as a super suspending agent,carrier,and redox mediator for sorbates during its migration from terrestrial to water bodies due to its unique properties such as high colloidal stability,strong sorption capacity,and high surface reactivity.The full implications of nano-BC in water/soil environments are far more than we expected.Thus,we call for more detailed investigations on the activity and reactivity of nano-BC in water/soil environments.
基金the National Natural Science Foundation of China(grant nos.22271009 and 22171015)Beijing Natural Science Foundation(grant no.2222003)Beijing Municipal Education Committee Project(grant nos.KZ202110005003 and KM202110005006).
文摘The electrochemical utilization of electron-deficient methylarenes for radical-radical cross-couplings remains very rare.Enabled by an umpolung strategy,the unprecedented electrochemical cross-coupling of electron-deficient methylarenes with aldehydes was developed.The paired electrolysis simultaneously generated electron-deficient benzylic radicals and ketyl radicals at both electrodes,which then underwent radical recombination,governed by polarity matching and persistent-radical effect(PRE)to afford functionalized alcohols that are not easily accessible by other methods.This protocol features catalystand external redox agent-free conditions and a formal 100%atom economy.Mechanistic studies support the radical-radical cross-coupling pathway.
