Efficient activation of molecular oxygen(O_(2))is considered a promising technique for the removal of antibiotics.However,how to effectively regulate electrons distribution to promote O_(2)activation remains a challen...Efficient activation of molecular oxygen(O_(2))is considered a promising technique for the removal of antibiotics.However,how to effectively regulate electrons distribution to promote O_(2)activation remains a challenge at present.In this study,phosphorus and sodium co-doped carbon nitride(PNaCN)were designed to rearrange the electrons distribution to activate O_(2)for the degradation of tetracycline.The generation of·O_(2)~-was innovatively observed via in-situ O_(2)fitting Fourier transform infrared(FTIR)spectroscopy,demonstrating the outstanding O_(2)activation ability of PNa5.Density functional theory(DFT)further confirmed that the rational co-doping led to the rearrangement of local electrons,resulting in electron-rich Na sites and electron-deficient P sites.These sites exhibited greater susceptibility to O_(2)adsorption and charge transfer.Besides,the degradation rate of tetracycline was increased by 2.44 times using co-doped CN.This study provides a new inspiration for enhancing O_(2)activation by inducing electrons rearrangement.展开更多
Acetaminophen(ACE)is commonly used in analgesic and antipyretic drug,which is hardly removed by traditional wastewater treatment processes.Herein,amorphous Co(OH)_(2)nanocages were explored as peroxymonosulfate(PMS)ac...Acetaminophen(ACE)is commonly used in analgesic and antipyretic drug,which is hardly removed by traditional wastewater treatment processes.Herein,amorphous Co(OH)_(2)nanocages were explored as peroxymonosulfate(PMS)activator for efficient degradation of ACE.In the presence of amorphous Co(OH)_(2)nanocages,100%of ACE removal was reached within 2 min with a reaction rate constant k_(1)=3.68 min 1 at optimum pH 5,which was much better than that of crystallineβ-Co(OH)_(2)and Co_(3)O_(4).Amorphous materials(disorder atom arrangement)with hollow structures possess large specific surface area,more reactive sites,and abundant vacancies structures,which could efficiently facilitate the catalytic redox reactions.The radicals quenching experiment demonstrated that SO_(4)^(·-)radicals dominated the ACE degradation rather than^(·)OH radicals.The mechanism of ACE degradation was elucidated by the an alysis of degradation in termediates and theoretical calculation,indicating that the electrophilic SO_(4)^(·-)and^(·)OH tend to attack the atoms of ACE with high Fukui index(f).Our finding highlights the remarkable advantages of amorphous materials as heterogeneous catalysts in sulfate radicals-based AOPs and sheds new lights on water treatment for the degradation of emerging organic contaminants.展开更多
Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(O...Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(OH)_(2)/BC)was fabricated by a simple and controllable method,which was used to degrade tetracycline hydrochloride(TTCH)in water through PAA activation.The results indicated that 100%TTCH(C_(0)=10μmol/L)degradation efficiency was realized within 7 min at pH 7,with a high kinetic rate constant(k_(1))of 0.64 min^(-1)by the optimized Co(OH)_(2)/BC.Material characterizations suggested that Co(OH)_(2)nanoparticle was successfully decorated on biochar,leading to more active sites and electronic structure alteration of biochar,thus greatly promoting the catalytic cleavage of PAA for radicals production.Then,the reactive oxygen species(ROS)quenching experiments and electron paramagnetic resonance(EPR)analysis demonstrated the key species were alkoxyl radicals(R–O^(·),mainly CH_(3)CO_(2)^(·)and CH_(3)CO_(3)^(·)),HO^(·)and^(1)O_(2)in this system.Besides,density functional theory(DFT)calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed.This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.展开更多
Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equiva...Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and sulfate.Methods: Samples were taken from two sites in Beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron microscopy.Results: The total deposition flux and total deposition velocity during the daytime were higher than those at night.Sulfate showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest Park.Conclusions: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry systems on particle removal and provide evidence for urban air pollution control and afforestation of urban areas.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21872102 and 22172080)the Fundamental Research Funds for the Central Universities,Nankai University(No.63231195)Tianjin“Project+Team”Innovation Team,2020。
文摘Efficient activation of molecular oxygen(O_(2))is considered a promising technique for the removal of antibiotics.However,how to effectively regulate electrons distribution to promote O_(2)activation remains a challenge at present.In this study,phosphorus and sodium co-doped carbon nitride(PNaCN)were designed to rearrange the electrons distribution to activate O_(2)for the degradation of tetracycline.The generation of·O_(2)~-was innovatively observed via in-situ O_(2)fitting Fourier transform infrared(FTIR)spectroscopy,demonstrating the outstanding O_(2)activation ability of PNa5.Density functional theory(DFT)further confirmed that the rational co-doping led to the rearrangement of local electrons,resulting in electron-rich Na sites and electron-deficient P sites.These sites exhibited greater susceptibility to O_(2)adsorption and charge transfer.Besides,the degradation rate of tetracycline was increased by 2.44 times using co-doped CN.This study provides a new inspiration for enhancing O_(2)activation by inducing electrons rearrangement.
基金Financial supports from China Postdoctoral Science Foundation (Nos.2019M650007 and 2020M670088)National NaturalScience Foundation of China (Nos.21906001,51721006)the Beijing Nova Program (No. Z19111000110000)
文摘Acetaminophen(ACE)is commonly used in analgesic and antipyretic drug,which is hardly removed by traditional wastewater treatment processes.Herein,amorphous Co(OH)_(2)nanocages were explored as peroxymonosulfate(PMS)activator for efficient degradation of ACE.In the presence of amorphous Co(OH)_(2)nanocages,100%of ACE removal was reached within 2 min with a reaction rate constant k_(1)=3.68 min 1 at optimum pH 5,which was much better than that of crystallineβ-Co(OH)_(2)and Co_(3)O_(4).Amorphous materials(disorder atom arrangement)with hollow structures possess large specific surface area,more reactive sites,and abundant vacancies structures,which could efficiently facilitate the catalytic redox reactions.The radicals quenching experiment demonstrated that SO_(4)^(·-)radicals dominated the ACE degradation rather than^(·)OH radicals.The mechanism of ACE degradation was elucidated by the an alysis of degradation in termediates and theoretical calculation,indicating that the electrophilic SO_(4)^(·-)and^(·)OH tend to attack the atoms of ACE with high Fukui index(f).Our finding highlights the remarkable advantages of amorphous materials as heterogeneous catalysts in sulfate radicals-based AOPs and sheds new lights on water treatment for the degradation of emerging organic contaminants.
基金supported by the National Key Research and Development Program of China(Nos.2022YFF1303102 and 2021YFA1202500)Beijing Natural Science Foundation(No.8232035)+2 种基金the National Natural Science Foundation of China(Nos.52270053,52200083 and 52200084)the Beijing Nova Program(No.20220484215)the Key Special Projects for Science and Technology of Inner Mongolia(No.2021EEDSCXSFQZD001)。
文摘Peracetic acid(CH_(3)C(O)OOH,PAA)-based heterogeneous advanced oxidation process(AOP)has attacked intensive interests due to production of various reactive species.Herein,Co(OH)_(2)nanoparticles decorated biochar(Co(OH)_(2)/BC)was fabricated by a simple and controllable method,which was used to degrade tetracycline hydrochloride(TTCH)in water through PAA activation.The results indicated that 100%TTCH(C_(0)=10μmol/L)degradation efficiency was realized within 7 min at pH 7,with a high kinetic rate constant(k_(1))of 0.64 min^(-1)by the optimized Co(OH)_(2)/BC.Material characterizations suggested that Co(OH)_(2)nanoparticle was successfully decorated on biochar,leading to more active sites and electronic structure alteration of biochar,thus greatly promoting the catalytic cleavage of PAA for radicals production.Then,the reactive oxygen species(ROS)quenching experiments and electron paramagnetic resonance(EPR)analysis demonstrated the key species were alkoxyl radicals(R–O^(·),mainly CH_(3)CO_(2)^(·)and CH_(3)CO_(3)^(·)),HO^(·)and^(1)O_(2)in this system.Besides,density functional theory(DFT)calculation on Fukui index further revealed that the vulnerable sites of TTCH and three possible degradation pathways were proposed.This study can provide a new strategy for synthesis functional materials in PAA activation AOPs for removal of antibiotics in water.
基金supported by the grants from the Beijing Collaborative Innovation Center for eco-environmental improvement with forestry and fruit trees(PXM2017_014207_000024)the Special Found for Beijing Common Construction Project for Beijing Laboratory of Urban and Rural Ecological Environment,Beijing Municipal Education Commission
文摘Background: Rapid economic development in China has resulted in an increase in severe air pollution in city groups such as the Beijing-Tianjin-Hebei Metropolitan Region. PM2.5(fine particles with an aerodynamic equivalent diameter of 2.5 μm or less) is one of the most important pollutants. The deposition process is an important way of removing particles from the air. To evaluate the effect of an urban forest on atmospheric particle removal, a concentration gradient method was used to measure the deposition velocities of water-soluble inorganics in PM2.5 in two national forest parks in Beijing, China. The following eight water-soluble inorganic ions in PM2.5 were investigated: sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, and sulfate.Methods: Samples were taken from two sites in Beijing from the 7 th to the 15 th May, 2013. The concentrations of water-soluble inorganic ions were analyzed with ion chromatography. We used the concentration gradient technique to estimate the deposition flux and velocity. To determine the relationships between leaf traits and particle accumulation, typical leaf samples from each selected species were studied using scanning electron microscopy.Results: The total deposition flux and total deposition velocity during the daytime were higher than those at night.Sulfate showed the biggest deposition flux and velocity at both study sites, whereas the other ions showed different trends at each site. Result from higher proportion of coniferous to broadleaved trees, the total deposition flux of the eight ions measured in Jiufeng National Forest Park was greater than that in Olympic Forest Park.Conclusions: The deposition velocity was affected by meteorological conditions such as wind speed, temperature,and humidity. The deposition velocity was also influenced by tree species. The surface of plants is an important factor influencing particle deposition. The results of this study may help in assessing the effects of forestry systems on particle removal and provide evidence for urban air pollution control and afforestation of urban areas.
