Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-...Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-pot method.Within the material,the nitrogen mainly exists as pyrrolyl nitrogen,which coordinates with iron to form an Fe-N structure that serves as the active site.The sensor incorporates acetylcholinesterase(AChE)to facilitate the restoration of oxidized 3,3',5',5'-tetramethylbenzidine(TMB),thereby restoring the blue solution to a color⁃less state.Furthermore,the presence of chlorpyrifos was found to inhibit AChE activity,causing the solution to turn blue again.A sensitive colorimetric method for chlorpyrifos has been established.The linear range of this method for the detection of chlorpyrifos was 0.90-80.00μg·g^(-1) and the limit of detection(LOD)was 0.13μg·g^(-1).When applied to real samples,the method achieved recoveries of 94.4%-109%for chlorpyrifos in soil,and relative standard devia⁃tions(RSD)of the assay were 3.6%-4.2%.Therefore,the constructed sensor holds significant potential for the reli⁃able detection of chlorpyrifos.展开更多
With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lign...With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.展开更多
In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions.The lignin structures were c...In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions.The lignin structures were characterized by Fourier transform infrared spectroscopy(FT-IR) and 1D and 2D Nuclear Magnetic Resonance(NMR).FT-IR spectra revealed that the "core" of the lignin structure did not significantly change during the treatment under the conditions given.The results of 1H and 13C NMR demonstrated that the lignin fraction L2,isolated with 70% ethanol containing 1% NaOH,was mainly composed of β-O-4 ether bonds together with G and S units and trace p-hydroxyphenyl unit.Based on the 2D HSQC NMR spectrum,the ethanol organosolv lignin fraction L1,extracted with 70% ethanol,presents a predominance of β-O-4′ aryl ether linkages(61% of total side chains),and a low abundance of condensed carbon-carbon linked structures(such as ββ′,β-1′,and β-5′) and a lower S/G ratio.Furthermore,a small percentage(ca.9%) of the linkage side chain was found to be acylated at the γ-carbon.展开更多
A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegr...A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegradation experiment was carried out in mineral salt medium, containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30℃. Under these conditions, significant reduction in color and lignin content by the strain was observed after incubation for 5 d. The strain attains maximum reduction capability in color （44.6%） and lignin content （39.9%） within 5 d of incubation, and reduced chemical oxygen demand（COD） from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day. The total ion chromatograph （TIC） of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments, indicating a strong destruction in the lignin structure.展开更多
Pyrolysis and combustion characteristics of three different oil cakes such as Pongamia(Pongamia Pinnata),Madhuca(Madhuca Indica),and Jatropha(Jatropha curcas) were investigated in this study.The cellulose and lignin c...Pyrolysis and combustion characteristics of three different oil cakes such as Pongamia(Pongamia Pinnata),Madhuca(Madhuca Indica),and Jatropha(Jatropha curcas) were investigated in this study.The cellulose and lignin contents of oil cakes play very important role in pyrolysis and combustion processes.A kinetic investigation of three oil cakes was carried out and major part of the samples decomposed between 210℃ and 500℃.Pyrolysis and combustion were carried out with the mixtures of cellulose and lignin chemicals in different ratios and compared with the oil cakes.The biomass with higher cellulose content showed faster rate of pyrolysis than the biomass with higher lignin content.However at higher temperatures(>600℃) all the oil cakes exhibited similar conversion at low heating rate in N2 atmosphere.Apparent activation energies increased for Madhuca and Pongamia oil cakes indicating the presence of more cellulose whereas,low activation energy of Jatropha confirms more lignin content.展开更多
基金The Fundamental Research Funds for the Central Universities(2572022DJ01)Natural Science Foundation of Heilongjiang Province(LH2022B002)。
文摘Nanomaterials exhibiting mimetic enzyme activity are promising candidates for colorimetric detection of chlorpyrifos.Herein,lignin-based FeN/C nanozymes(FeN/CNs)with peroxidase-like activity were synthesized by a one-pot method.Within the material,the nitrogen mainly exists as pyrrolyl nitrogen,which coordinates with iron to form an Fe-N structure that serves as the active site.The sensor incorporates acetylcholinesterase(AChE)to facilitate the restoration of oxidized 3,3',5',5'-tetramethylbenzidine(TMB),thereby restoring the blue solution to a color⁃less state.Furthermore,the presence of chlorpyrifos was found to inhibit AChE activity,causing the solution to turn blue again.A sensitive colorimetric method for chlorpyrifos has been established.The linear range of this method for the detection of chlorpyrifos was 0.90-80.00μg·g^(-1) and the limit of detection(LOD)was 0.13μg·g^(-1).When applied to real samples,the method achieved recoveries of 94.4%-109%for chlorpyrifos in soil,and relative standard devia⁃tions(RSD)of the assay were 3.6%-4.2%.Therefore,the constructed sensor holds significant potential for the reli⁃able detection of chlorpyrifos.
基金National Natural Science Foundation of China(22262034)。
文摘With the development of electronics and portable devices,there is a significant drive to develop electrode materials for supercapacitors that are lightweight,economical,and provide high energy and power densities.Lignin-based porous carbons have recently been extensively studied for en-ergy storage applications because of their characteristics of large specific surface area,easy doping,and high conductivity.Significant progress in the synthesis of porous carbons derived from lignin,using different strategies for their preparation and modification with heteroatoms,metal oxides,met-al sulfides,and conductive polymers is considered and their electrochemical performances and ion storage mechanisms are discussed.Considerable fo-cus is directed towards the challenges encountered in using lignin-based por-ous carbons and the ways to optimize specific capacity and energy density for supercapacitor applications.Finally,the limitations of existing technolo-gies and research directions for improving the performance of lignin-based carbons are discussed.
基金Major State Basic Research Projects of China(973-2010CB732204)Specific Programs in Graduate Science and Technology Innovation of Beijing Forestry University(BLYJ201110)
文摘In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions.The lignin structures were characterized by Fourier transform infrared spectroscopy(FT-IR) and 1D and 2D Nuclear Magnetic Resonance(NMR).FT-IR spectra revealed that the "core" of the lignin structure did not significantly change during the treatment under the conditions given.The results of 1H and 13C NMR demonstrated that the lignin fraction L2,isolated with 70% ethanol containing 1% NaOH,was mainly composed of β-O-4 ether bonds together with G and S units and trace p-hydroxyphenyl unit.Based on the 2D HSQC NMR spectrum,the ethanol organosolv lignin fraction L1,extracted with 70% ethanol,presents a predominance of β-O-4′ aryl ether linkages(61% of total side chains),and a low abundance of condensed carbon-carbon linked structures(such as ββ′,β-1′,and β-5′) and a lower S/G ratio.Furthermore,a small percentage(ca.9%) of the linkage side chain was found to be acylated at the γ-carbon.
基金Project(50925417) supported by the National Funds for Distinguished Young Scientists,ChinaProject(50830301) supported by the Key program of the National Natural Science Foundation of ChinaProject(2012BAC12B03) supported by the National 12th Five-year Plan for Science and Technology Support,China
文摘A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy, and identified as Pandoraea sp. by 16S rRNA gene sequence analysis. The biodegradation experiment was carried out in mineral salt medium, containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30℃. Under these conditions, significant reduction in color and lignin content by the strain was observed after incubation for 5 d. The strain attains maximum reduction capability in color （44.6%） and lignin content （39.9%） within 5 d of incubation, and reduced chemical oxygen demand（COD） from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day. The total ion chromatograph （TIC） of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments, indicating a strong destruction in the lignin structure.
文摘Pyrolysis and combustion characteristics of three different oil cakes such as Pongamia(Pongamia Pinnata),Madhuca(Madhuca Indica),and Jatropha(Jatropha curcas) were investigated in this study.The cellulose and lignin contents of oil cakes play very important role in pyrolysis and combustion processes.A kinetic investigation of three oil cakes was carried out and major part of the samples decomposed between 210℃ and 500℃.Pyrolysis and combustion were carried out with the mixtures of cellulose and lignin chemicals in different ratios and compared with the oil cakes.The biomass with higher cellulose content showed faster rate of pyrolysis than the biomass with higher lignin content.However at higher temperatures(>600℃) all the oil cakes exhibited similar conversion at low heating rate in N2 atmosphere.Apparent activation energies increased for Madhuca and Pongamia oil cakes indicating the presence of more cellulose whereas,low activation energy of Jatropha confirms more lignin content.
