The activated nitrogen-enriched novel carbons (NENCs) were prepared by direct carbonization using polyaniline coating activated mesocarbon microbead composites as the precursor. Herein the influences of the carbonizat...The activated nitrogen-enriched novel carbons (NENCs) were prepared by direct carbonization using polyaniline coating activated mesocarbon microbead composites as the precursor. Herein the influences of the carbonization temperature on the structure and morphology of the NENCs samples were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 adsorption/desorption isotherm at 77 K. The electrochemical properties of the supercapacitors were characterized by cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS), cycle life, leakage current and self-discharge measurements in 6 mol/L KOH solution. The results demonstrate that the NENC samples carbonized at 600 °C show the highest specific capacitance of 385 F/g at the current density of 1 A/g and the lowest ESR value (only 0.93?). Furthermore, the capacity retention ratio of the NENCs-600 supercapacitor is 92.8 % over 2500 cycles.展开更多
As a vital chemical,ammonia(NH3)plays an irreplaceable role in many fields such as chemical synthesis and energy storage.Green renewable biomass can be converted into biofuels,but its nitrogen resources are underused ...As a vital chemical,ammonia(NH3)plays an irreplaceable role in many fields such as chemical synthesis and energy storage.Green renewable biomass can be converted into biofuels,but its nitrogen resources are underused throughout.Laser-driven pyrolysis is envisaged to debuts as a bridge to connect them to realize the direct conversion from nitrogen-rich biomass into ammonia.The pulsed laser-induced local-transient thermal effect recognized the biological nitrogen resources conversion,such as cheap and plentiful yeasts,to small gaseous molecules and achieved spectacular ammonia production rate up to 260.4 mg/h,an order of magnitude higher performance than thermochemical ammonia synthesis.Simultaneously,the tiny hot point generated by a low-energy laser(20W)guarantees the whole ammonia synthesis reaction systemis in amild environment of low temperature and normal pressure.Additionally,the remaining solid residue after laser-driven pyrolysis also can be further exploited as a highly active catalyst for electrocatalytic nitrate reduction reaction(NIRR).展开更多
Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA ...Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data.The mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional PMF.However,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in winter.Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA.The compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass spectrum.Aged biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,respectively.Aged BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA sources.Compared to aged BBOA,aged CCOA was more subject to conversion during aqueous phase processing.These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.展开更多
Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generati...Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.展开更多
Mitigation of toxic contaminants from wastewater is crucial to the safety and sustainability of the aquatic ecosystem and human health.There is a pressing need to find economical and efficient technologies for municip...Mitigation of toxic contaminants from wastewater is crucial to the safety and sustainability of the aquatic ecosystem and human health.There is a pressing need to find economical and efficient technologies for municipal,agricultural,aquacultural,and industrial wastewater treatment.Nitrogen-doped biochar,which is synthesized from waste biomass,is shown to exhibit good adsorptive performance towards harmful aqueous contaminants,including heavy metals and organic chemicals.Incor-porating nitrogen into the biochar matrix changes the overall electronic structure of biochar,which favors the interaction of N-doped biochar with contaminants.In this review,we start the discussion with the preparation techniques and raw materials used for the production of N-doped biochar,along with its structural attributes.Next,the adsorption of heavy metals and organic pollutants on N-doped biochars is systematically discussed.The adsorption mechanisms of contaminant removal by N-doped biochar are also clearly explained.Further,mathematical analyses of adsorption,crucial to the quantification of adsorption,process design,and understanding of the mechanics of the process,are reviewed.Furthermore,the influence of environmental parameters on the adsorption process and the reusability of N-doped biochars are critically evaluated.Finally,future research trends for the design and development of application-specific preparation of N-doped biochars for wastewater treatment are suggested.展开更多
基金Projects(51072173,51272221)supported by the National Natural Science Foundation of ChinaProject(20094301110005)supported by Specialized Research Fund for the Doctoral Program of Higher Education,ChinaProject(2013FJ4062)supported by Science and Technology Plan Foundation of Hunan Province,China
文摘The activated nitrogen-enriched novel carbons (NENCs) were prepared by direct carbonization using polyaniline coating activated mesocarbon microbead composites as the precursor. Herein the influences of the carbonization temperature on the structure and morphology of the NENCs samples were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N2 adsorption/desorption isotherm at 77 K. The electrochemical properties of the supercapacitors were characterized by cyclic voltammetry, galvanostatic charge/discharge, electrochemical impedance spectroscopy (EIS), cycle life, leakage current and self-discharge measurements in 6 mol/L KOH solution. The results demonstrate that the NENC samples carbonized at 600 °C show the highest specific capacitance of 385 F/g at the current density of 1 A/g and the lowest ESR value (only 0.93?). Furthermore, the capacity retention ratio of the NENCs-600 supercapacitor is 92.8 % over 2500 cycles.
基金Taishan Scholar Project of Shandong Province,Grant/Award Number:tsqn201812083Natural Science Foundation of Shandong Province,Grant/Award Numbers:ZR2021JQ15,ZR2022YQ42,ZR2020QE057,2022GJJLJRC-01+1 种基金Innovative Team Project of Jinan,Grant/Award Number:2021GXRC019National Natural Science Foundation of China,Grant/Award Numbers:51972147,52022037,52202366。
文摘As a vital chemical,ammonia(NH3)plays an irreplaceable role in many fields such as chemical synthesis and energy storage.Green renewable biomass can be converted into biofuels,but its nitrogen resources are underused throughout.Laser-driven pyrolysis is envisaged to debuts as a bridge to connect them to realize the direct conversion from nitrogen-rich biomass into ammonia.The pulsed laser-induced local-transient thermal effect recognized the biological nitrogen resources conversion,such as cheap and plentiful yeasts,to small gaseous molecules and achieved spectacular ammonia production rate up to 260.4 mg/h,an order of magnitude higher performance than thermochemical ammonia synthesis.Simultaneously,the tiny hot point generated by a low-energy laser(20W)guarantees the whole ammonia synthesis reaction systemis in amild environment of low temperature and normal pressure.Additionally,the remaining solid residue after laser-driven pyrolysis also can be further exploited as a highly active catalyst for electrocatalytic nitrate reduction reaction(NIRR).
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0760200)the National Natural Science Foundation of China(Grant No.42377101,91744207).
文摘Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data.The mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional PMF.However,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in winter.Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA.The compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass spectrum.Aged biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,respectively.Aged BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA sources.Compared to aged BBOA,aged CCOA was more subject to conversion during aqueous phase processing.These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.
基金supported by Funding of Jiangsu Innovation Program for Graduate Education of China (No.KYLX15_0231)Postgraduate Research & Practice Innovation Program of Jiangsu Province of China (No.KYCX17_0279)+1 种基金the Fundamental Research Funds for the Central Universities,Aviation Industry Corporation of China Technology Innovation Fund for Fundamental Research (No.2014D60931R)Funding of Ministry of Industry and Information Technology for Civil Aircraft
文摘Fuel tank inerting technologies are able to reduce the fire risk by injection of inert gas into the ullage or fuel, the former called ullage washing and the latter fuel scrubbing. The Green On-Board Inert Gas Generation System（GOBIGGS） is a novel technology based on flameless catalytic combustion, and owning to its simple structure and high inerting efficiency, it has received a lot of attentions. The inert gas in the GOBIGGS is mainly comprised of CO2, N2, and O2（hereinafter, Mixed Inert Gas（MIG））, while that in the On-Board Inert Gas Generation System（OBIGGS）, which is one of the most widely used fuel tank inerting technologies, is NitrogenEnriched Air（NEA）. The solubility of CO2 is nearly 20 times higher than that of N2 in jet fuels,so the inerting capability and performance are definitely disparate if the inert gas is selected as NEA or MIG. An inerting test bench was constructed to compare the inerting capabilities between NEA and MIG. Experimental results reveal that, if ullage washing is adopted, the variations of oxygen concentrations on the ullage and in the fuel are nearly identical no matter the inert gas is NEA or MIG. However, the ullage and dissolved oxygen concentrations of MIG scrubbing are always higher than those of NEA scrubbing.
文摘Mitigation of toxic contaminants from wastewater is crucial to the safety and sustainability of the aquatic ecosystem and human health.There is a pressing need to find economical and efficient technologies for municipal,agricultural,aquacultural,and industrial wastewater treatment.Nitrogen-doped biochar,which is synthesized from waste biomass,is shown to exhibit good adsorptive performance towards harmful aqueous contaminants,including heavy metals and organic chemicals.Incor-porating nitrogen into the biochar matrix changes the overall electronic structure of biochar,which favors the interaction of N-doped biochar with contaminants.In this review,we start the discussion with the preparation techniques and raw materials used for the production of N-doped biochar,along with its structural attributes.Next,the adsorption of heavy metals and organic pollutants on N-doped biochars is systematically discussed.The adsorption mechanisms of contaminant removal by N-doped biochar are also clearly explained.Further,mathematical analyses of adsorption,crucial to the quantification of adsorption,process design,and understanding of the mechanics of the process,are reviewed.Furthermore,the influence of environmental parameters on the adsorption process and the reusability of N-doped biochars are critically evaluated.Finally,future research trends for the design and development of application-specific preparation of N-doped biochars for wastewater treatment are suggested.
