A H_(2)O_(2)etching strategy was adopted to introduce coordinatively unsaturated sites(CUS)on MoS_(2)-based catalysts for dibenzothiophene(DBT)hydrodesulfurization(HDS).The CUS concentrations on MoS_(2) slabs were fin...A H_(2)O_(2)etching strategy was adopted to introduce coordinatively unsaturated sites(CUS)on MoS_(2)-based catalysts for dibenzothiophene(DBT)hydrodesulfurization(HDS).The CUS concentrations on MoS_(2) slabs were finely regulated by changing the concentrations of H_(2)O_(2)solution.With the increasing H_(2)O_(2)concentrations(0.1–0.3 mol/L),The CUS concentrations on MoS_(2) slabs increased gradually.However,the high-concentration H_(2)O_(2)etching(0.5 mol/L)increased the MoOxSy and MoO_(3) contents on MoS_(2) slabs compared to etching with the H_(2)O_(2)concentration of 0.3 mol/L,which led to the less CUS concentration in the sulfided Mo–H-0.5 catalyst than in the sulfided Mo–H-0.3 catalyst.A microstructure-activity correlation indicated that the CUS introduced by H_(2)O_(2)etching on MoS_(2) slabs significantly enhanced DBT HDS.Different Co loadings were further introduced into Mo–H-0.3,which had the most CUS concentration,and the corresponding 0.2-CoMo catalyst with the highest CoMoS content(3.853 wt%)exhibited the highest reaction rate constant of 6.95×10^(−6)mol g^(−1)s^(−1)among these CoMo catalysts.展开更多
Various metal-modified ZSM-5 zeolite adsorbents prepared by the impregnation method were applied to the removal of organic chlorides from model naphtha.The adsorption performance and regeneration stability were invest...Various metal-modified ZSM-5 zeolite adsorbents prepared by the impregnation method were applied to the removal of organic chlorides from model naphtha.The adsorption performance and regeneration stability were investigated by static adsorption experiments.The morphologies,structural features,and physicochemical properties of the adsorbents were characterized by X-ray diffraction,Brunauer-Emmett-Teller analysis,NH3 temperature-programmed desorption,scanning electron microscopy,transmission electron microscopy,and pyridine adsorption infrared spectroscopy.The Mg/ZSM-5 zeolite adsorbent possessed a relatively high specific surface area and good metal dispersion and exhibited the best dechlorination and regeneration performance.The characterization results revealed that introduction of the metal exerted a significant influence on the acidic properties of the catalyst surface.A decrease in the ratio of Brønsted acidic sites to Lewis acidic sites and an increase in the amount of moderately acidic sites were confirmed to be responsible for the excellent adsorption performance of the Mg-modified ZSM-5 zeolite.Furthermore,the Langmuir adsorption isotherm model was applied to study the adsorption equilibrium and thermodynamics of the Mg/ZSM-5 adsorbent under mild conditions.The results revealed that the removal of 1,2-dichloroethane by the Mg/ZSM-5 adsorbent was endothermic,spontaneous,disordered,and primarily involved physical adsorption.展开更多
Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttl...Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttle effect.In this work,the small organic molecules of 2,5-dichloropyrazine(2,5-DCP)were combined with Co-doped carbon(CoA NAC)flakes to achieve the synergic effect of the covalent and chemical sulfur fixation,so as that the immobilization-conversion of polysulfides in LSBs was greatly enhanced.More specifically,the nucleophilic substitution of the 2,5-DCP additive in the electrolyte with polysulfides formed the CAS bonds.Through the further covalent N-Li bonds between the N atoms in 2,5-DCP and polysulfides,sulfur fixation was achieved in the form of solid organosulfur.Meanwhile,the CoA NAC flakes served as the sulfur cathode to chemically anchor the polysulfides.The interaction mechanism between CoA NAC/2,5-DCP and polysulfides was explored by the density functional theory(DFT)calculations and in-situ infrared spectroscopy.The results showed that the optimal“with 2,5-DCP”sample-assembled LSB exhibited an initial discharge specific capacity of 1244 mA h g^(-1)at 0.2C,and a capacity decay rate of 0.053%per cycle was displayed after 800 cycles at 1C.The good cycling stability with a high sulfur-loaded electrode sample suggested that the synergic effect of covalent/chemical sulfur fixation enabled the enhancement of polysulfides immobilization-conversion in LSBs.展开更多
In this work,modified g-C_(3)N_(4) was fabricated successfully by calcination of ionic liquid(IL) and urea.The addition of IL changed the polymerization mode of urea,induced the self-assembly of urea molecules,modifie...In this work,modified g-C_(3)N_(4) was fabricated successfully by calcination of ionic liquid(IL) and urea.The addition of IL changed the polymerization mode of urea,induced the self-assembly of urea molecules,modified the morphological structure of the tightly packed g-C_(3)N_(4),and extended the electron conjugation system.When using 1-butyl-3-methylimidazolium chloride([Bmim]Cl) as a modifier,the heteroatom Cl could be inserted into the g-C_(3)N_(4) to optimize the electronic structure.The results of characterizations indicate that the unique structure of modified g-C_(3)N_(4) has an expanded electron delocalization range,introduces an interlayer charge transmission channel,promotes the charge transmission,reduces the band gap,enhances the absorption of visible light,and inhibits electron-hole recombination.Modified g-C_(3)N_(4) showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline.Furthermore,the effect of different anions in 1-butyl-3-methylimidazolium salts([Bmim]Cl,[Bmim]Br,[Bmim][BF_(4)],and [Bmim][PF_6]) on the structure and function of g-C_(3) N_(4) are discussed.展开更多
NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms chara...NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms characterized by X-ray photoelectron spectroscopy was contemporaneous inverse manipulated.The optimized NiCoP_(4)O_(12)/NiCoP arrays have a high specific capacitance of 507.8μAh∙cm^(–2)at 1 mA∙cm^(–2),and good rate ability of 64.7%retention at 30-folds increased current density.Importantly,an ultra-stable ability,88.5%of retention after 10000 cycles,was achieved in an asymmetric cell assembled of the NiCoP_(4)O_(12)/NiCoP arrays with activated carbon.In addition,the energy and power densities of an asymmetric cell were higher than those of other work,demonstrating as-prepared NiCoP_(4)O_(12)/NiCoP arrays are promising electrodes for supercapacitors.展开更多
Antimony selenide(Sb_(2)Se_(3))is one of the perspective candidates for potassium-ion batteries due to its advanced virtues stem including featured high capacity,fertile reserves and the relative narrow band gap.Despi...Antimony selenide(Sb_(2)Se_(3))is one of the perspective candidates for potassium-ion batteries due to its advanced virtues stem including featured high capacity,fertile reserves and the relative narrow band gap.Despite the unique advantages,it is still plagued by the unstable interface compatibility and poor wider-temperature adaptability.The optimization of microstructure and the construction of inorganic-organic hybrids with a low desolvation barrier and rapid kinetics behaviors are efficient to address these issues.The Sb_(2)Se_(3)nanorods enclosed by the S-doped carbon layer(SC),further crosslinked by the poly(N-isopropylacrylamide)(PM)film(PM@Sb_(2)Se_(3)@SC),were artificially fabricated,and it displays the enrichment ion aggregated model as well as contacted ion pair state,the well-tailored cooperation environment of potassium bonds,assuring a homogeneous potassium deposition and an excellent widertemperature adaptability.The complicated experimental studies and theoretical calculations authenticate the synergistic effects of geometric conformation and compositional design for the tremendously enhanced potassium storage.Moreover,the full device over PM@Sb_(2)Se_(3)@SC anode and the potassium Prussian blue cathode manifests impressively durable cycling life and wider-temperature adaptability,verifying the glorious contribution from the finely manipulation in solvation structure and potassium bonds to enhancing the potassium storage behaviors.展开更多
Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this stu...Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this study,a method was developed to synthesize directly porous Ni2P nanosheet arrays and Ni2P nanoparticles onto nickel foam via a hydrothermal reaction followed by a phosphorization process.Mechanistic studies revealed that the allomorphs of Ni2P nanosheets and Ni2P nanoparticles in the array-like structure were formed via the Kirkendall effect and Ostwald ripening.A fully functional water electrolyzer containing Ni2P as electrodes for the OER and HER exhibited promising activity and stability.At 10 mA·cm^−2,a Ni2P cell voltage of 1.63 V was obtained,which was only 0.05 V smaller than that found for Pt/C/NF||RuO2/NF cell.The enhanced electrocatalytic performance resulted from the favorable porosity of the Ni2P arrays and the synergistic effect between Ni2P nanosheets and Ni2P nanoparticles.展开更多
Pectin is a kind of natural hydrophilic colloid with complicated composition and structure,which has been abundantly found in the cells of higher plants.Pectin has good water solubility,stability,gelling ability and e...Pectin is a kind of natural hydrophilic colloid with complicated composition and structure,which has been abundantly found in the cells of higher plants.Pectin has good water solubility,stability,gelling ability and emulsifying ability,as well as safety and non-toxicity,good biocompatibility,biodegradability,and many excellent biological activities such as lowering cholesterol,anti-tumor,anti-oxidation,and lowering blood sugar.Moreover,both its physicochemical properties and functional performance can be further improved by physical,chemical and enzymatic treatments and compound modification upon the active functional groups,such as hydroxyl groups,carboxyl groups and glycosidic bonds.Therefore,pectin has been widely used in many fields,including food industry and pharmaceutical industry.Furthermore,great application potential has emerged in daily-use chemical industry,functional materials,and biodegradable biological materials.In this review,the source,chemical structure,main physicochemical properties and functional characteristics of pectin were briefly introduced.The extraction methods,separation and purification technologies,and modification methods for pectin were also systematically presented.In addition,the situation of application as well as the current problems for pectin and its modified products were summarized.Finally,some of the directions of future research and development of pectin were pointed out.展开更多
Ubiquitination, a key and extensive posttranslational modification of proteins, has profound effects on a variety of physiological and pathological processes. The inherent complexity of ubiquitin conjugates makes it h...Ubiquitination, a key and extensive posttranslational modification of proteins, has profound effects on a variety of physiological and pathological processes. The inherent complexity of ubiquitin conjugates makes it highly challenging to study the functional and structural mechanisms of ubiquitination. To address these challenges, accesses to sufficient poly-ubiquitin chains or ubiquitinated proteins are urgently needed. Over the last decade, synthetic protein chemists have developed several novel peptide ligation methods for the preparation of ubiquitin conjugates with precise control over the atomic structure. In this review, we summarize the recent breakthroughs and potential challenges in the chemical synthesis and semi-synthesis of ubiquitin conjugates with respect to the preparation of poly-ubiquitin-based proteins and ubiquitin-based probes.展开更多
Abundant FeS2 with high theoretical capacity is one of the promising anode candidates in sodium-ion batteries(SlBs),however,the uneven sodium deposition due to the poor interface compatibility and sluggish reaction ki...Abundant FeS2 with high theoretical capacity is one of the promising anode candidates in sodium-ion batteries(SlBs),however,the uneven sodium deposition due to the poor interface compatibility and sluggish reaction kinetics because of the high activation barrier still plague its practical application.Herein,we synthesized the ordered porous carbon matrix wrapped FeS2 nanoparticles(FeS_2@OCN)with high sodium wettability and low pore tortuosity to economically enhance the interface compatibility as well as to lower the energy barrier in SIBs.The synergistic effects of low tortuosity pores and strong sodium wettability homogenize the Na+flux distribution,bring the electron dislocation via the enrichment of edgenitrogen(Pyridinic N and Pyrrolic N),thus achieving the dendrite-free sodium deposition and dramatically enhanced reaction kinetics.Benefiting from exceptional structural/compositional/electronic merits,the resultant anode is endowed with exceptional structure stability,achieving long-term cycling stability of 451.9 mAh·g^(-1)after 1000cycles at 1 A·g^(-1)with specific capacity retention of 92.9%.Attenuated electrode tortuosity and high sodium wettability can corporately improve the interface compatibility and attenuate the activation barrier of the FeS_2 host and beyond.展开更多
The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability.Considering the close connection between their...The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability.Considering the close connection between their performance and the amount of carbon material loaded on the electrodes,in this work,NiCo_(2)O_(4) nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction.Then,the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo_(2)O_(4) nanowires,and the obtained composite was used as electrode for electric double layer capacitor.The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF·cm^(-2) at the current density of 1 mA·cm^(-2).The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW·h·cm^(-3) at a power density of 180 mW·cm^(-3).The assembled symmetric capacitor exhibited a capacitance retention of 88.96%after 10000 charge/discharge cycles at the current density of 20 mA·cm^(-2).These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.展开更多
A series of novel 5?alkoxyfuran-2(5H)-one derivatives was synthesized, and characterized by 1H NMR, 13C NMR and HRMS. Biological activities of all the title compounds were evaluated systematically. Preliminary bioassa...A series of novel 5?alkoxyfuran-2(5H)-one derivatives was synthesized, and characterized by 1H NMR, 13C NMR and HRMS. Biological activities of all the title compounds were evaluated systematically. Preliminary bioassays indicated that most of the compounds exhibited moderate insecticidal activities against Aphis craccivora and Nilaparvata lugens at 100 mg/L. Compounds 4h and 4w exhibited 100% mortality rate against Aphis craccivora at 100 mg/L, and compound 4h exhibited good mortality rate against Aphis craccivora and Nilaparvata lugens (60% and 75%, respectively) even at 4 mg/L. The results demonstrated the impact of various chemical groups on insecticidal activities and provided a potential clue for further exploring novel high-effective broad-spectrum insecticides.展开更多
Flexible electronic devices based on reversible bonds for self-curing capabilities arouses extensive interest.However,most of the composite conductive elastomers have the problems of poor mechanical properties and slo...Flexible electronic devices based on reversible bonds for self-curing capabilities arouses extensive interest.However,most of the composite conductive elastomers have the problems of poor mechanical properties and slow recovery of mechanical properties during multiple stretching,which hinder their stability in continuous operation.In this study,hyperbranched-MWCNTs/hyperbranched-PDMS self-healable conductive elastomers inspired by cephalopods were successfully developed.The prepared conductive elastomer exhibited good self-healing ability(91%)at room temperature excited by multiple reversible interactions.The prepared elastomer showed outstanding mechanical properties and anti-fatigue ability,so that it can cope with more arduous tasks.Moreover,the elastomer was sensitive to the change of stress states and can be used as a stable strain sensor.Therefore,the self-repairing conductive elastomer has potential practicability in the fields of human-computer interaction,motion monitoring,soft robot and so on.展开更多
基金support of the National Natural Science Foundation of China(Grant Nos.21978323 and 22108145).
文摘A H_(2)O_(2)etching strategy was adopted to introduce coordinatively unsaturated sites(CUS)on MoS_(2)-based catalysts for dibenzothiophene(DBT)hydrodesulfurization(HDS).The CUS concentrations on MoS_(2) slabs were finely regulated by changing the concentrations of H_(2)O_(2)solution.With the increasing H_(2)O_(2)concentrations(0.1–0.3 mol/L),The CUS concentrations on MoS_(2) slabs increased gradually.However,the high-concentration H_(2)O_(2)etching(0.5 mol/L)increased the MoOxSy and MoO_(3) contents on MoS_(2) slabs compared to etching with the H_(2)O_(2)concentration of 0.3 mol/L,which led to the less CUS concentration in the sulfided Mo–H-0.5 catalyst than in the sulfided Mo–H-0.3 catalyst.A microstructure-activity correlation indicated that the CUS introduced by H_(2)O_(2)etching on MoS_(2) slabs significantly enhanced DBT HDS.Different Co loadings were further introduced into Mo–H-0.3,which had the most CUS concentration,and the corresponding 0.2-CoMo catalyst with the highest CoMoS content(3.853 wt%)exhibited the highest reaction rate constant of 6.95×10^(−6)mol g^(−1)s^(−1)among these CoMo catalysts.
基金This work was financially supported by the Natural Science Foundation of Shandong Province(ZR2021MB134 and ZR2022MB019)the National Natural Science Foundation of China(22008131)+1 种基金the Talent Fund for Province and Ministry Co-construction Collaborative Innovation Center of Eco-chemical Engineering(STHGYX2220)the Opening Fund of State Key Laboratory of Heavy Oil Processing(SKLOP202002002).
文摘Various metal-modified ZSM-5 zeolite adsorbents prepared by the impregnation method were applied to the removal of organic chlorides from model naphtha.The adsorption performance and regeneration stability were investigated by static adsorption experiments.The morphologies,structural features,and physicochemical properties of the adsorbents were characterized by X-ray diffraction,Brunauer-Emmett-Teller analysis,NH3 temperature-programmed desorption,scanning electron microscopy,transmission electron microscopy,and pyridine adsorption infrared spectroscopy.The Mg/ZSM-5 zeolite adsorbent possessed a relatively high specific surface area and good metal dispersion and exhibited the best dechlorination and regeneration performance.The characterization results revealed that introduction of the metal exerted a significant influence on the acidic properties of the catalyst surface.A decrease in the ratio of Brønsted acidic sites to Lewis acidic sites and an increase in the amount of moderately acidic sites were confirmed to be responsible for the excellent adsorption performance of the Mg-modified ZSM-5 zeolite.Furthermore,the Langmuir adsorption isotherm model was applied to study the adsorption equilibrium and thermodynamics of the Mg/ZSM-5 adsorbent under mild conditions.The results revealed that the removal of 1,2-dichloroethane by the Mg/ZSM-5 adsorbent was endothermic,spontaneous,disordered,and primarily involved physical adsorption.
基金the financially supports from the National Natural Science Foundation of China(51963004)the Natural Science Foundation of Shandong Province of China(ZR2020MB024)。
文摘Lithium-sulfur batteries(LSBs)are promising as the next generation energy storage options.However,their wide applications have been technically challenged by the diffusion losses of polysulfides and polysulfide shuttle effect.In this work,the small organic molecules of 2,5-dichloropyrazine(2,5-DCP)were combined with Co-doped carbon(CoA NAC)flakes to achieve the synergic effect of the covalent and chemical sulfur fixation,so as that the immobilization-conversion of polysulfides in LSBs was greatly enhanced.More specifically,the nucleophilic substitution of the 2,5-DCP additive in the electrolyte with polysulfides formed the CAS bonds.Through the further covalent N-Li bonds between the N atoms in 2,5-DCP and polysulfides,sulfur fixation was achieved in the form of solid organosulfur.Meanwhile,the CoA NAC flakes served as the sulfur cathode to chemically anchor the polysulfides.The interaction mechanism between CoA NAC/2,5-DCP and polysulfides was explored by the density functional theory(DFT)calculations and in-situ infrared spectroscopy.The results showed that the optimal“with 2,5-DCP”sample-assembled LSB exhibited an initial discharge specific capacity of 1244 mA h g^(-1)at 0.2C,and a capacity decay rate of 0.053%per cycle was displayed after 800 cycles at 1C.The good cycling stability with a high sulfur-loaded electrode sample suggested that the synergic effect of covalent/chemical sulfur fixation enabled the enhancement of polysulfides immobilization-conversion in LSBs.
基金support provided by the National Natural Science Foundation of China (21878164, 21978143)Shandong Provincial Key Research and Development Program (2019GGX102029)+1 种基金“Qing Chuang Science and Technology Plan” Project of Colleges and Universities in Shandong Province (2020KJC005)State Key Laboratory of Materials-Oriented Chemical Engineering-Open Fund (KL19-08)。
文摘In this work,modified g-C_(3)N_(4) was fabricated successfully by calcination of ionic liquid(IL) and urea.The addition of IL changed the polymerization mode of urea,induced the self-assembly of urea molecules,modified the morphological structure of the tightly packed g-C_(3)N_(4),and extended the electron conjugation system.When using 1-butyl-3-methylimidazolium chloride([Bmim]Cl) as a modifier,the heteroatom Cl could be inserted into the g-C_(3)N_(4) to optimize the electronic structure.The results of characterizations indicate that the unique structure of modified g-C_(3)N_(4) has an expanded electron delocalization range,introduces an interlayer charge transmission channel,promotes the charge transmission,reduces the band gap,enhances the absorption of visible light,and inhibits electron-hole recombination.Modified g-C_(3)N_(4) showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline.Furthermore,the effect of different anions in 1-butyl-3-methylimidazolium salts([Bmim]Cl,[Bmim]Br,[Bmim][BF_(4)],and [Bmim][PF_6]) on the structure and function of g-C_(3) N_(4) are discussed.
基金he Natural Science Foundation of Shandong Province of China(Grant No.ZR2020MB024)and the Open Project Program of Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices,Huizhou University(Grant No.EFMD2021001Z)for financially supporting this work.
文摘NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms characterized by X-ray photoelectron spectroscopy was contemporaneous inverse manipulated.The optimized NiCoP_(4)O_(12)/NiCoP arrays have a high specific capacitance of 507.8μAh∙cm^(–2)at 1 mA∙cm^(–2),and good rate ability of 64.7%retention at 30-folds increased current density.Importantly,an ultra-stable ability,88.5%of retention after 10000 cycles,was achieved in an asymmetric cell assembled of the NiCoP_(4)O_(12)/NiCoP arrays with activated carbon.In addition,the energy and power densities of an asymmetric cell were higher than those of other work,demonstrating as-prepared NiCoP_(4)O_(12)/NiCoP arrays are promising electrodes for supercapacitors.
基金financially supported by the National Natural Science Foundation of China(No.22175103)Young Taishan Scholar project of Shandong province。
文摘Antimony selenide(Sb_(2)Se_(3))is one of the perspective candidates for potassium-ion batteries due to its advanced virtues stem including featured high capacity,fertile reserves and the relative narrow band gap.Despite the unique advantages,it is still plagued by the unstable interface compatibility and poor wider-temperature adaptability.The optimization of microstructure and the construction of inorganic-organic hybrids with a low desolvation barrier and rapid kinetics behaviors are efficient to address these issues.The Sb_(2)Se_(3)nanorods enclosed by the S-doped carbon layer(SC),further crosslinked by the poly(N-isopropylacrylamide)(PM)film(PM@Sb_(2)Se_(3)@SC),were artificially fabricated,and it displays the enrichment ion aggregated model as well as contacted ion pair state,the well-tailored cooperation environment of potassium bonds,assuring a homogeneous potassium deposition and an excellent widertemperature adaptability.The complicated experimental studies and theoretical calculations authenticate the synergistic effects of geometric conformation and compositional design for the tremendously enhanced potassium storage.Moreover,the full device over PM@Sb_(2)Se_(3)@SC anode and the potassium Prussian blue cathode manifests impressively durable cycling life and wider-temperature adaptability,verifying the glorious contribution from the finely manipulation in solvation structure and potassium bonds to enhancing the potassium storage behaviors.
基金The authors would like to thank the National Natural Science Foundation of China(Nos.51661008 and 21766032)Key Technology Research and Development Program of Shandong(No.2019GGX103029)for financially supporting this work.
文摘Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this study,a method was developed to synthesize directly porous Ni2P nanosheet arrays and Ni2P nanoparticles onto nickel foam via a hydrothermal reaction followed by a phosphorization process.Mechanistic studies revealed that the allomorphs of Ni2P nanosheets and Ni2P nanoparticles in the array-like structure were formed via the Kirkendall effect and Ostwald ripening.A fully functional water electrolyzer containing Ni2P as electrodes for the OER and HER exhibited promising activity and stability.At 10 mA·cm^−2,a Ni2P cell voltage of 1.63 V was obtained,which was only 0.05 V smaller than that found for Pt/C/NF||RuO2/NF cell.The enhanced electrocatalytic performance resulted from the favorable porosity of the Ni2P arrays and the synergistic effect between Ni2P nanosheets and Ni2P nanoparticles.
文摘Pectin is a kind of natural hydrophilic colloid with complicated composition and structure,which has been abundantly found in the cells of higher plants.Pectin has good water solubility,stability,gelling ability and emulsifying ability,as well as safety and non-toxicity,good biocompatibility,biodegradability,and many excellent biological activities such as lowering cholesterol,anti-tumor,anti-oxidation,and lowering blood sugar.Moreover,both its physicochemical properties and functional performance can be further improved by physical,chemical and enzymatic treatments and compound modification upon the active functional groups,such as hydroxyl groups,carboxyl groups and glycosidic bonds.Therefore,pectin has been widely used in many fields,including food industry and pharmaceutical industry.Furthermore,great application potential has emerged in daily-use chemical industry,functional materials,and biodegradable biological materials.In this review,the source,chemical structure,main physicochemical properties and functional characteristics of pectin were briefly introduced.The extraction methods,separation and purification technologies,and modification methods for pectin were also systematically presented.In addition,the situation of application as well as the current problems for pectin and its modified products were summarized.Finally,some of the directions of future research and development of pectin were pointed out.
基金supported by the National Natural Science Foundation of China (21807063, 91753120, U1732161, 81503094)the start-up grant from Qingdao University (41118010086)the China Postdoctoral Science Foundation (2016 M600524)
文摘Ubiquitination, a key and extensive posttranslational modification of proteins, has profound effects on a variety of physiological and pathological processes. The inherent complexity of ubiquitin conjugates makes it highly challenging to study the functional and structural mechanisms of ubiquitination. To address these challenges, accesses to sufficient poly-ubiquitin chains or ubiquitinated proteins are urgently needed. Over the last decade, synthetic protein chemists have developed several novel peptide ligation methods for the preparation of ubiquitin conjugates with precise control over the atomic structure. In this review, we summarize the recent breakthroughs and potential challenges in the chemical synthesis and semi-synthesis of ubiquitin conjugates with respect to the preparation of poly-ubiquitin-based proteins and ubiquitin-based probes.
基金financially supported by the National Natural Science Foundation of China (Nos.22175103 and 22178191)。
文摘Abundant FeS2 with high theoretical capacity is one of the promising anode candidates in sodium-ion batteries(SlBs),however,the uneven sodium deposition due to the poor interface compatibility and sluggish reaction kinetics because of the high activation barrier still plague its practical application.Herein,we synthesized the ordered porous carbon matrix wrapped FeS2 nanoparticles(FeS_2@OCN)with high sodium wettability and low pore tortuosity to economically enhance the interface compatibility as well as to lower the energy barrier in SIBs.The synergistic effects of low tortuosity pores and strong sodium wettability homogenize the Na+flux distribution,bring the electron dislocation via the enrichment of edgenitrogen(Pyridinic N and Pyrrolic N),thus achieving the dendrite-free sodium deposition and dramatically enhanced reaction kinetics.Benefiting from exceptional structural/compositional/electronic merits,the resultant anode is endowed with exceptional structure stability,achieving long-term cycling stability of 451.9 mAh·g^(-1)after 1000cycles at 1 A·g^(-1)with specific capacity retention of 92.9%.Attenuated electrode tortuosity and high sodium wettability can corporately improve the interface compatibility and attenuate the activation barrier of the FeS_2 host and beyond.
基金the Natural Science Foundation of Shandong Province of China (Grant No.ZR2020MB024)for financially supporting this work.
文摘The bind-free carbon cloth-supported electrodes hold the promises for high-performance electrochemical capacitors with high specific capacitance and good cyclic stability.Considering the close connection between their performance and the amount of carbon material loaded on the electrodes,in this work,NiCo_(2)O_(4) nanowires were firstly grown on the substrate of active carbon cloth to provide the necessary surface area in the longitudinal direction.Then,the quinone-rich nitrogen-doped carbon shell structure was formed around NiCo_(2)O_(4) nanowires,and the obtained composite was used as electrode for electric double layer capacitor.The results showed that the composite electrode displayed an area-specific capacitance of 1794 mF·cm^(-2) at the current density of 1 mA·cm^(-2).The assembled symmetric electric double layer capacitor achieved a high energy density of 6.55 mW·h·cm^(-3) at a power density of 180 mW·cm^(-3).The assembled symmetric capacitor exhibited a capacitance retention of 88.96%after 10000 charge/discharge cycles at the current density of 20 mA·cm^(-2).These results indicated the potentials in the preparation of the carbon electrode materials with high energy density and good cycling stability.
基金Supported by the Natural Science Foundation of Shandong Province,China(No.ZR2018MB013)the National Natural Science Foundation of China(No.21501066)the Key Research and Development Program of Shandong Province,China (No.2016GGX 107006).
文摘A series of novel 5?alkoxyfuran-2(5H)-one derivatives was synthesized, and characterized by 1H NMR, 13C NMR and HRMS. Biological activities of all the title compounds were evaluated systematically. Preliminary bioassays indicated that most of the compounds exhibited moderate insecticidal activities against Aphis craccivora and Nilaparvata lugens at 100 mg/L. Compounds 4h and 4w exhibited 100% mortality rate against Aphis craccivora at 100 mg/L, and compound 4h exhibited good mortality rate against Aphis craccivora and Nilaparvata lugens (60% and 75%, respectively) even at 4 mg/L. The results demonstrated the impact of various chemical groups on insecticidal activities and provided a potential clue for further exploring novel high-effective broad-spectrum insecticides.
基金This work was financially supported by Shandong Provincial Natural Science Foundation(No.ZR2019QB019)the National Natural Science Foundation of China(No.51872150)+1 种基金Shandong Provincial Natural Science Foundation(No.ZR2018MB034)Key Laboratory of Special Functional Aggregated Materials,Ministry of Education,P.R.China,“QingChuang Science and Technology Plan”Project of Colleges and Universities in Shandong Province(No.2020KJC005).
文摘Flexible electronic devices based on reversible bonds for self-curing capabilities arouses extensive interest.However,most of the composite conductive elastomers have the problems of poor mechanical properties and slow recovery of mechanical properties during multiple stretching,which hinder their stability in continuous operation.In this study,hyperbranched-MWCNTs/hyperbranched-PDMS self-healable conductive elastomers inspired by cephalopods were successfully developed.The prepared conductive elastomer exhibited good self-healing ability(91%)at room temperature excited by multiple reversible interactions.The prepared elastomer showed outstanding mechanical properties and anti-fatigue ability,so that it can cope with more arduous tasks.Moreover,the elastomer was sensitive to the change of stress states and can be used as a stable strain sensor.Therefore,the self-repairing conductive elastomer has potential practicability in the fields of human-computer interaction,motion monitoring,soft robot and so on.
