First-principle calculations were performed to study the adsorption of boron and its relationship with the morphologies of Ti C.It is found that although the adsorption of boron on all the low-index Ti C crystal plane...First-principle calculations were performed to study the adsorption of boron and its relationship with the morphologies of Ti C.It is found that although the adsorption of boron on all the low-index Ti C crystal planes is thermally favorable,it will be adsorbed more easily by C-terminated {111} and {011} planes,while less possible to be adsorbed by {001}.The study of the formation of B–B clusters indicates that the distribution of boron adatoms on C-terminated（111） and {011} planes will be more uniform,and the diffusion of the adatom further confirms the above results.According to the geometry relationship and growth rate of different crystal planes,it is deduced that the adsorption of boron on Ti C will seriously impede the growth of {111} and {011} planes,which can make Ti C grow into hexagonal platelets.展开更多
Recently,reactive oxygen species(ROS)-independent mimetics of oxidase with Au nanoclusters(NCs)as the catalysts and MnO_(2)as electron acceptor have gained attention.In this study,we aim to explore the oxidase-mimicki...Recently,reactive oxygen species(ROS)-independent mimetics of oxidase with Au nanoclusters(NCs)as the catalysts and MnO_(2)as electron acceptor have gained attention.In this study,we aim to explore the oxidase-mimicking potential of bovine serum albumin(BSA)-templated metal nanoclusters(BSA-M NCs,where M=Ag,Pt,Cu,or Cd)beyond Au NCs in boosting the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)by MnO_(2),denoted as BM@Metal.The oxidase-mimetic activity of BM@Metal is independent of ROS and generally enhanced by the incorporation of metal nanoclusters.Notably,this enhancement varies with the metal species,with BSA-Cd exhibiting the highest activity.The X-ray photoelectron spectroscopy(XPS)analysis confirms mixed valence states(Mn(Ⅳ)/Mn(Ⅱ))in BM@Cd.Given that the catalytic activity is closely linked to the substrate adsorption,the label-free isothermal titration calorimetry was employed to probe the affinity between TMB and BSA-M NCs,which provides a robust approach for probing the interface adsorption.The results reveal that the superior catalytic performance of BSA-Cd correlates with enhanced TMB adsorption,likely facilitated by coordination and hydrophobic interactions.Finally,the superior catalytic performance of BSA-M NCs on the oxidation of TMB by MnO_(2)has inspired us to fabricate the assay for analyzing α-glucosidase’s activity.This work not only demonstrates the versatility of metal NCs in constructing ROS-independent oxidase mimetics but also provides interfacial adsorption engineered strategy for the rational design of superior ROS independent mimetics of natural oxidase.展开更多
Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution...Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution.There is a need for green and sustainable solutions to remove air pollutants,as opposed to conventional techniques which can be expensive,consume additional energy and generate further waste.We developed a novel integrated bioreactor combined with recyclable iron oxide nano/micro-particle adsorption interfaces,to remove CO_2,and undesired organic air pollutants using natural particles,while generating oxygen.This semi-continuous bench-scale photo-bioreactor was shown to successfully clean up simulated emission streams of up to 45% CO_2 with a conversion rate of approximately 4%CO_2 per hour,generating a steady supply of oxygen（6 mmol/hr）,while nanoparticles effectively remove several undesired organic by-products.We also showed algal waste of the bioreactor can be used for mercury remediation.We estimated the potential CO_2 emissions that could be captured from our new method for three industrial cases in which,coal,oil and natural gas were used.With a 30% carbon capture system,the reduction of CO_2 was estimated to decrease by about 420,000,320,000 and 240,000 metric tonnes,respectively for a typical 500 MW power plant.The cost analysis we conducted showed potential to scale-up,and the entire system is recyclable and sustainable.We further discuss the implications of usage of this complete system,or as individual units,that could provide a hybrid option to existing industrial setups.展开更多
This paper is concerned with the dispersion of particles on the fluid-liquid interface. In a previous study we have shown that when small particles, e.g., flour, pollen, glass beads, etc., contact an air-liquid interf...This paper is concerned with the dispersion of particles on the fluid-liquid interface. In a previous study we have shown that when small particles, e.g., flour, pollen, glass beads, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. In this paper we show that motion of particles normal to the interface is inertia dominated; they oscillate vertically about their equilibrium position before coming to rest under viscous drag. This vertical motion of a particle causes a radially-outward lateral （secondary） flow on the interface that causes nearby particles to move away. The dispersion on a liquid-liquid interface, which is the primary focus of this study, was relatively weaker than on an air-liquid interface, and occurred over a longer period of time. When falling through an upper liquid the particles have a slower velocity than when falling through air because the liquid has a greater viscosity. Another difference for the liquid-liquid interface is that the separation of particles begins in the upper liquid before the particles reach the interface. The rate of dispersion depended on the size of the particles, the densities of the particle and liquids, the viscosities of the liquids involved, and the contact angle. For small particles, partial pinning and hysteresis of the three-phase contact line on the surface of the particle during adsorption on liquid-liquid interfaces was also important. The frequency of oscillation of particles about their floating equilibrium increased with decreasing particle size on both air-water and liquid-liquid interfaces, and the time to reach equilibrium decreased with decreasing particle size. These results are in agreement with our analysis.展开更多
Nitriles as efficient electrolyte additives are widely used in high-voltage lithium-ion batteries.However,their working mechanisms are still mysterious,especially in practical high-voltage LiCoO_(2)pouch lithium-ion b...Nitriles as efficient electrolyte additives are widely used in high-voltage lithium-ion batteries.However,their working mechanisms are still mysterious,especially in practical high-voltage LiCoO_(2)pouch lithium-ion batteries.Herein,we adopt a tridentate ligandcontaining 1,3,6-hexanetricarbonitrile(HTCN)as an effective electrolyte additive to shed light on the mechanism of stabilizing high-voltage LiCoO_(2)cathode(4.5 V)through nitriles.The LiCoO_(2)/graphite pouch cells with the HTCN additive electrolyte possess superior cycling performance,90%retention of the initial capacity after 800 cycles at 25℃,and 72%retention after 500 cycles at 45℃,which is feasible for practical application.Such an excellent cycling performance can be attributed to the stable interface:The HTCN molecules with strong electron-donating ability participate in the construction of cathode-electrolyte interphase(CEI)through coordinating with Co ions,which suppresses the decomposition of electrolyte and improves the structural stability of LiCoO_(2)during cycling.In summary,the work recognizes a coordinating-based interphase-forming mechanism as an effective strategy to optimize the performance of high voltage LiCoO_(2)cathode with appropriate electrolyte additives for practical pouch batteries.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51301068)the Natural Science Foundation of Hebei Province (No.E2014502003 and A2013502120)the Fundamental Research Funds for the Central Universities (No.2014MS116)
文摘First-principle calculations were performed to study the adsorption of boron and its relationship with the morphologies of Ti C.It is found that although the adsorption of boron on all the low-index Ti C crystal planes is thermally favorable,it will be adsorbed more easily by C-terminated {111} and {011} planes,while less possible to be adsorbed by {001}.The study of the formation of B–B clusters indicates that the distribution of boron adatoms on C-terminated（111） and {011} planes will be more uniform,and the diffusion of the adatom further confirms the above results.According to the geometry relationship and growth rate of different crystal planes,it is deduced that the adsorption of boron on Ti C will seriously impede the growth of {111} and {011} planes,which can make Ti C grow into hexagonal platelets.
基金the financial support from the National Natural Science Foundation of China(Nos.22073025,21603067,and U23A2089)the Program of Science and Technology Plan of the City of Tianjin(No.24JRRCRC00040)+1 种基金Opening Fund of Hubei Key Laboratory of Bioinorganic Chemistry&Materia Medica(No.BCMM202507)the Open Fund of Hubei Key Laboratory of Resources and Chemistry of Chinese Medicine(No.KLRCCM2404).
文摘Recently,reactive oxygen species(ROS)-independent mimetics of oxidase with Au nanoclusters(NCs)as the catalysts and MnO_(2)as electron acceptor have gained attention.In this study,we aim to explore the oxidase-mimicking potential of bovine serum albumin(BSA)-templated metal nanoclusters(BSA-M NCs,where M=Ag,Pt,Cu,or Cd)beyond Au NCs in boosting the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)by MnO_(2),denoted as BM@Metal.The oxidase-mimetic activity of BM@Metal is independent of ROS and generally enhanced by the incorporation of metal nanoclusters.Notably,this enhancement varies with the metal species,with BSA-Cd exhibiting the highest activity.The X-ray photoelectron spectroscopy(XPS)analysis confirms mixed valence states(Mn(Ⅳ)/Mn(Ⅱ))in BM@Cd.Given that the catalytic activity is closely linked to the substrate adsorption,the label-free isothermal titration calorimetry was employed to probe the affinity between TMB and BSA-M NCs,which provides a robust approach for probing the interface adsorption.The results reveal that the superior catalytic performance of BSA-Cd correlates with enhanced TMB adsorption,likely facilitated by coordination and hydrophobic interactions.Finally,the superior catalytic performance of BSA-M NCs on the oxidation of TMB by MnO_(2)has inspired us to fabricate the assay for analyzing α-glucosidase’s activity.This work not only demonstrates the versatility of metal NCs in constructing ROS-independent oxidase mimetics but also provides interfacial adsorption engineered strategy for the rational design of superior ROS independent mimetics of natural oxidase.
基金supported by Natural Sciences and Engineering Research Council of Canada(NSERC)-NSERC CREATE Mine of Knowledge,FRQNT(Fonds de recherche du Québec-Nature et Technologies),and Environment Canada
文摘Fossil fuel combustion and many industrial processes generate gaseous emissions that contain a number of toxic organic pollutants and carbon dioxide（CO_2） which contribute to climate change and atmospheric pollution.There is a need for green and sustainable solutions to remove air pollutants,as opposed to conventional techniques which can be expensive,consume additional energy and generate further waste.We developed a novel integrated bioreactor combined with recyclable iron oxide nano/micro-particle adsorption interfaces,to remove CO_2,and undesired organic air pollutants using natural particles,while generating oxygen.This semi-continuous bench-scale photo-bioreactor was shown to successfully clean up simulated emission streams of up to 45% CO_2 with a conversion rate of approximately 4%CO_2 per hour,generating a steady supply of oxygen（6 mmol/hr）,while nanoparticles effectively remove several undesired organic by-products.We also showed algal waste of the bioreactor can be used for mercury remediation.We estimated the potential CO_2 emissions that could be captured from our new method for three industrial cases in which,coal,oil and natural gas were used.With a 30% carbon capture system,the reduction of CO_2 was estimated to decrease by about 420,000,320,000 and 240,000 metric tonnes,respectively for a typical 500 MW power plant.The cost analysis we conducted showed potential to scale-up,and the entire system is recyclable and sustainable.We further discuss the implications of usage of this complete system,or as individual units,that could provide a hybrid option to existing industrial setups.
文摘This paper is concerned with the dispersion of particles on the fluid-liquid interface. In a previous study we have shown that when small particles, e.g., flour, pollen, glass beads, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. In this paper we show that motion of particles normal to the interface is inertia dominated; they oscillate vertically about their equilibrium position before coming to rest under viscous drag. This vertical motion of a particle causes a radially-outward lateral （secondary） flow on the interface that causes nearby particles to move away. The dispersion on a liquid-liquid interface, which is the primary focus of this study, was relatively weaker than on an air-liquid interface, and occurred over a longer period of time. When falling through an upper liquid the particles have a slower velocity than when falling through air because the liquid has a greater viscosity. Another difference for the liquid-liquid interface is that the separation of particles begins in the upper liquid before the particles reach the interface. The rate of dispersion depended on the size of the particles, the densities of the particle and liquids, the viscosities of the liquids involved, and the contact angle. For small particles, partial pinning and hysteresis of the three-phase contact line on the surface of the particle during adsorption on liquid-liquid interfaces was also important. The frequency of oscillation of particles about their floating equilibrium increased with decreasing particle size on both air-water and liquid-liquid interfaces, and the time to reach equilibrium decreased with decreasing particle size. These results are in agreement with our analysis.
基金supported by the National Key Research and Development Program of China(Nos.2017YFA0206700 and 2017YFA0402802)the National Natural Science Foundation of China(Nos.21776265 and 51902304)Anhui Provincial Natural Science Foundation(No.1908085ME122).
文摘Nitriles as efficient electrolyte additives are widely used in high-voltage lithium-ion batteries.However,their working mechanisms are still mysterious,especially in practical high-voltage LiCoO_(2)pouch lithium-ion batteries.Herein,we adopt a tridentate ligandcontaining 1,3,6-hexanetricarbonitrile(HTCN)as an effective electrolyte additive to shed light on the mechanism of stabilizing high-voltage LiCoO_(2)cathode(4.5 V)through nitriles.The LiCoO_(2)/graphite pouch cells with the HTCN additive electrolyte possess superior cycling performance,90%retention of the initial capacity after 800 cycles at 25℃,and 72%retention after 500 cycles at 45℃,which is feasible for practical application.Such an excellent cycling performance can be attributed to the stable interface:The HTCN molecules with strong electron-donating ability participate in the construction of cathode-electrolyte interphase(CEI)through coordinating with Co ions,which suppresses the decomposition of electrolyte and improves the structural stability of LiCoO_(2)during cycling.In summary,the work recognizes a coordinating-based interphase-forming mechanism as an effective strategy to optimize the performance of high voltage LiCoO_(2)cathode with appropriate electrolyte additives for practical pouch batteries.
