Seawater electrolysis offers a promising pathway to generate green hydrogen,which is crucial for the net-zero emission targets.Indirect seawater electrolysis is severely limited by high energy demands and system compl...Seawater electrolysis offers a promising pathway to generate green hydrogen,which is crucial for the net-zero emission targets.Indirect seawater electrolysis is severely limited by high energy demands and system complexity,while the direct seawater electrolysis bypasses pre-treatment,offering a simpler and more cost-effective solution.However,the chlorine evolution reaction and impurities in the seawater lead to severe corrosion and hinder electrolysis’s efficiency.Herein,we review recent advances in the rational design of chlorine-suppressive catalysts and integrated electrolysis systems architectures for chloride-induced corrosion,with simultaneous enhancement of Faradaic efficiency and reduction of electrolysis’s cost.Furthermore,promising directions are proposed for durable and efficient seawater electrolysis systems.This review provides perspectives for seawater electrolysis toward sustainable energy conversion and environmental protection.展开更多
This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and ch...This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the effect of photolysis on ozone concentrations, ozone depletion, total ozone abundance, and ozone layer along the altitude in the stratosphere. The calculated ozone concentrations and profile of the layer followed a similar trend and were generally in good agreement with the measurements above the tropical area. The calculated peak of the layer was at the same mid-stratosphere at Z = 30 km with a peak concentration and total ozone abundance about 20% higher than the measured peak concentration of 8.0 ppm and total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone concentrations and total abundance were substantially reduced. Cl generally depleted more uniformly of ozone across the altitude, while ClO reduced substantially the ozone in the upper stratosphere and thus shifted the peak of the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are active ozone-depleting chemicals, ClO was found to have a more pronounced impact on ozone depletion and distribution than Cl. The possible explanations of these interesting phenomena were discussed and elaborated. The approach and calculations in this paper were shown to be useful in providing an initial insight into the structure and behavior of the complex ozone layer.展开更多
Spinel cobalt oxide(Co_(3)O_(4)),consisting of tetrahedral Co^(2+)(CoTd)and octahedral Co^(3+)(CoOh),is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction(CER).Identifying the catal...Spinel cobalt oxide(Co_(3)O_(4)),consisting of tetrahedral Co^(2+)(CoTd)and octahedral Co^(3+)(CoOh),is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction(CER).Identifying the catalytic contribution of geometric Co site in the electrocatalytic CER plays a pivotal role to precisely modulate electronic configuration of active Co sites to boost CER.Herein,combining density functional theory calculations and experiment results assisted with operando analysis,we found that the Co_(Oh) site acts as the main active site for CER in spinel Co_(3)O_(4),which shows better Cl^(-)adsorption and more moderate intermediate adsorption toward CER than CoTd site,and does not undergo redox transition under CER condition at applied potentials.Guided by above findings,the oxygen vacancies were further introduced into the Co_(3)O_(4) to precisely manipulate the electronic configuration of Co_(Oh) to boost Cl^(-)adsorption and optimize the reaction path of CER and thus to enhance the intrinsic CER activity significantly.Our work figures out the importance of geometric configuration dependent CER activity,shedding light on the rational design of advanced electrocatalysts from geometric configuration optimization at the atomic level.展开更多
The stacking and aggregation of graphene nanosheets have been obstacles to their application as electrode materials for microelectronic devices.This study deploys a one-step,scalable,facile electrochemical exfoliation...The stacking and aggregation of graphene nanosheets have been obstacles to their application as electrode materials for microelectronic devices.This study deploys a one-step,scalable,facile electrochemical exfoliation technique to fabricate nitrogen(N)and chlorine(Cl)co-doped graphene nanosheets(i.e.,N-Cl-G)via the application of constant voltage on graphite in a mixture of 0.1 mol/L H_(2)SO_(4)and 0.1 mol/L NH_(4)Cl without using dangerous and exhaustive operation.The introduction of Cl(with its large radius)and N,both with high electrical negativity,facilitates the modulation of the electronic structure of graphene and creation of rich structural defects in it.Consequently,in the as-constructed supercapacitors,N-Cl-G exhibits a high specific capacitance of 77 F/g at 0.2 A/g and remarkable cycling stability with 91.7%retention of initial capacitance after 20,000 cycles at 10 A/g.Furthermore,a symmetrical supercapacitor assembled with N-Cl-G as the positive and negative electrodes(denoted as N-Cl-G//N-Cl-G)exhibits an energy density of 3.38 Wh/kg at a power density of 600 W/kg and superior cycling stability with almost no capacitance loss after 5000 cycles at 5 A/g.This study provides a scalable protocol for the facile fabrication of high-performance co-doped graphene as an electrode material candidate for supercapacitors.展开更多
To investigate the effect of chlorine roasting on the migration and removal of trace elements in quartz lattice,firstly,an efficient pretreatment process,grinding–HCl washing–flotation–HF and HCl leaching,was used ...To investigate the effect of chlorine roasting on the migration and removal of trace elements in quartz lattice,firstly,an efficient pretreatment process,grinding–HCl washing–flotation–HF and HCl leaching,was used to remove the gangue minerals in quartz ore to obtain purified quartz for the preparation of high-purity quartz and the investigation of lattice impurities migration.The results showed that the high-purity quartz with total impurities less than 50μg/g could be obtained from purified quartz after being treated with chlorine at 1200°C.The variation of crystal structure and the lattice impurities migration of quartz during chlorine roasting were studied through in-situ XRD,TGA,SEM-EDS,ICP-MS,FT-IR and XPS analysis.It revealed that the decomposable impurities H_(2)O,-OH,and residual collectors in the crystal of purified quartz could be effectively removed through chlorine roasting above 900°C,which also had an obvious effect on the removal of low-valence trace elements Li,Na and K in the crystal of quartz but didn't affect the multivalent trace elements Al and Ti.This study revealed the removal and migration mechanism of the trace elements in quartz crystal during chlorine roasting.展开更多
The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on ...The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on a boron-doped diamond (BDD) electrode. The hydroxyl radicals were quantified indirectly by assaying the samples from the HClO4 (0.1 M) electrolysis with a 10−4 M potassium permanganate solution. The investigations showed that the amount of hydroxyl radicals depends on the concentration of HClO4 and the current density. As for chlorine, a qualitative determination was carried out. A mixture of the electrolyte solution of HClO4 (0.1 M) + NaI (0.2 M) + 2 mL of hexane, taken in this order, leads to a purplish-pink coloration attesting to the presence of Cl2. The same test was carried out with NaBr and NaI giving pale and very pale pink colourations, respectively, showing that the intensity of the colouration depends on the strength of the oxidant present. In addition, oxidants were detected during the electrooxidation of metronidazole (MNZ). The results showed the participation of electrogenerated hydroxyl radicals. The generation of chlorine has also been proven. Furthermore, the degradation leads to a chemical oxygen demand (COD) removal rate of 83.48% and the process is diffusion-controlled.展开更多
Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,spec...Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.展开更多
High-efficiency seawater electrolysis is impeded by the low activity and low durability of oxygen evolution catalysts due to the complex composition and competitive side reactions in seawater.Herein,a heterogeneousstr...High-efficiency seawater electrolysis is impeded by the low activity and low durability of oxygen evolution catalysts due to the complex composition and competitive side reactions in seawater.Herein,a heterogeneousstructured catalyst is constructed by depositing NiFe-layered double hydroxides(NiFe-LDH)on the substrate of MXene(V_(2)CT_(x))modified Ni foam(NF),and abbreviated as NiFe-LDH/V_(2)CT_(x)/NF.As demonstrated,owing to the intrinsic negative charge characteristic of V_(2)CT_(x),chlorine ions are denied entry to the interface between NiFeLDH and V_(2)CT_(x)/NF substrate,thus endowing NiFe-LDH/V_(2)CT_(x)/NF catalyst with high corrosion resistance and durable stability for 110 h at 500 mA cm^(-2).Meanwhile,the two-dimensional structure and high electrical conductivity of V_(2)CT_(x) can respectively enlarge the electrochemical active surface area and guarantee fast charge transfer,thereby synergistically promoting the catalytic performance of NiFe-LDH/V_(2)CT_(x)/NF in both deionized water electrolyte(261 m V at 100 m A cm^(-2))and simulated seawater electrolyte(241 mV at 100 mA cm^(-2)).This work can guide the preparation of oxygen evolution catalysts and accelerate the industrialization of seawater electrolysis.展开更多
Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are st...Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.展开更多
This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozon...This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere.展开更多
挥发性氯化溶剂被广泛应用在纺织产品生产、加工及后处理过程中,其残留会损害人体健康,破坏环境。在纺织品领域,2020版0eko-tex Standard 100首次将氯化溶剂纳入附录6、附录7,并对其含量和总量做出了限定。如何快速、准确测定纺织品中...挥发性氯化溶剂被广泛应用在纺织产品生产、加工及后处理过程中,其残留会损害人体健康,破坏环境。在纺织品领域,2020版0eko-tex Standard 100首次将氯化溶剂纳入附录6、附录7,并对其含量和总量做出了限定。如何快速、准确测定纺织品中氯化溶剂残留已经成为业界关注的重点。文中详细介绍了氯化溶剂残留的来源、危害、限量、目前的样品采集方法及检测方法等,并对方法的原理和优缺点进行了分析,可以帮助检测人员找到合适的检验方法,减少实验误差,提高检测能力,为生态纺织品的标准体系建设提供技术支持。展开更多
A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found...A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found were 1.0×10^-5 for CI and 1.3×10^-6 for Br. The measuring range of the method found were 0.3-20.0 mg/L for CI and 4,0-120,0 μg/L for Br. The results obtained agreed quite well with those reference values.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22208376,UA22A20429)Shandong Provincial Natural Science Foundation(Nos.ZR2024QB175,ZR2023LFG005)+1 种基金Qingdao New Energy Shandong Laboratory Open Project(QNESL OP 202303)Ministry of Education University-Industry Collaborative Education Program(No.230804132140429).
文摘Seawater electrolysis offers a promising pathway to generate green hydrogen,which is crucial for the net-zero emission targets.Indirect seawater electrolysis is severely limited by high energy demands and system complexity,while the direct seawater electrolysis bypasses pre-treatment,offering a simpler and more cost-effective solution.However,the chlorine evolution reaction and impurities in the seawater lead to severe corrosion and hinder electrolysis’s efficiency.Herein,we review recent advances in the rational design of chlorine-suppressive catalysts and integrated electrolysis systems architectures for chloride-induced corrosion,with simultaneous enhancement of Faradaic efficiency and reduction of electrolysis’s cost.Furthermore,promising directions are proposed for durable and efficient seawater electrolysis systems.This review provides perspectives for seawater electrolysis toward sustainable energy conversion and environmental protection.
文摘This paper presents a system approach of mass balance calculations of ozone and other species under diffusion-convection-reaction processes to study the impacts of major ozone-depleting chemicals, chlorine (Cl) and chlorine monoxide (ClO), and the effect of photolysis on ozone concentrations, ozone depletion, total ozone abundance, and ozone layer along the altitude in the stratosphere. The calculated ozone concentrations and profile of the layer followed a similar trend and were generally in good agreement with the measurements above the tropical area. The calculated peak of the layer was at the same mid-stratosphere at Z = 30 km with a peak concentration and total ozone abundance about 20% higher than the measured peak concentration of 8.0 ppm and total abundance of 399 DU. In the presence of Cl and ClO, the calculated ozone concentrations and total abundance were substantially reduced. Cl generally depleted more uniformly of ozone across the altitude, while ClO reduced substantially the ozone in the upper stratosphere and thus shifted the peak of the layer to a much lower elevation at Z = 14 km. Although both ClO and Cl are active ozone-depleting chemicals, ClO was found to have a more pronounced impact on ozone depletion and distribution than Cl. The possible explanations of these interesting phenomena were discussed and elaborated. The approach and calculations in this paper were shown to be useful in providing an initial insight into the structure and behavior of the complex ozone layer.
基金the National Natural Science Foundation of China(U21A20286,22206054 and 21805069)Natural Science Foundation of Hubei(2021CFB094)the Fundamental Research Funds for the Central China Normal University(CCNU)for financial support。
文摘Spinel cobalt oxide(Co_(3)O_(4)),consisting of tetrahedral Co^(2+)(CoTd)and octahedral Co^(3+)(CoOh),is considered as promising earth-abundant electrocatalyst for chlorine evolution reaction(CER).Identifying the catalytic contribution of geometric Co site in the electrocatalytic CER plays a pivotal role to precisely modulate electronic configuration of active Co sites to boost CER.Herein,combining density functional theory calculations and experiment results assisted with operando analysis,we found that the Co_(Oh) site acts as the main active site for CER in spinel Co_(3)O_(4),which shows better Cl^(-)adsorption and more moderate intermediate adsorption toward CER than CoTd site,and does not undergo redox transition under CER condition at applied potentials.Guided by above findings,the oxygen vacancies were further introduced into the Co_(3)O_(4) to precisely manipulate the electronic configuration of Co_(Oh) to boost Cl^(-)adsorption and optimize the reaction path of CER and thus to enhance the intrinsic CER activity significantly.Our work figures out the importance of geometric configuration dependent CER activity,shedding light on the rational design of advanced electrocatalysts from geometric configuration optimization at the atomic level.
基金supported by National Science Foundation of China(No.52201254)Natural Science Foundation of Shandong Province(Nos.ZR2020MB090,ZR2020MB027,and ZR2020QE012)+1 种基金the project of“20 Items of University”of Jinan(No.202228046)the Taishan Scholar Project of Shandong Province(No.tsqn202306226)。
文摘The stacking and aggregation of graphene nanosheets have been obstacles to their application as electrode materials for microelectronic devices.This study deploys a one-step,scalable,facile electrochemical exfoliation technique to fabricate nitrogen(N)and chlorine(Cl)co-doped graphene nanosheets(i.e.,N-Cl-G)via the application of constant voltage on graphite in a mixture of 0.1 mol/L H_(2)SO_(4)and 0.1 mol/L NH_(4)Cl without using dangerous and exhaustive operation.The introduction of Cl(with its large radius)and N,both with high electrical negativity,facilitates the modulation of the electronic structure of graphene and creation of rich structural defects in it.Consequently,in the as-constructed supercapacitors,N-Cl-G exhibits a high specific capacitance of 77 F/g at 0.2 A/g and remarkable cycling stability with 91.7%retention of initial capacitance after 20,000 cycles at 10 A/g.Furthermore,a symmetrical supercapacitor assembled with N-Cl-G as the positive and negative electrodes(denoted as N-Cl-G//N-Cl-G)exhibits an energy density of 3.38 Wh/kg at a power density of 600 W/kg and superior cycling stability with almost no capacitance loss after 5000 cycles at 5 A/g.This study provides a scalable protocol for the facile fabrication of high-performance co-doped graphene as an electrode material candidate for supercapacitors.
基金provided by the National Natural Science Foundation of China(No.52374273)the China Postdoctoral Science Foundation Project(No.2023M731041)。
文摘To investigate the effect of chlorine roasting on the migration and removal of trace elements in quartz lattice,firstly,an efficient pretreatment process,grinding–HCl washing–flotation–HF and HCl leaching,was used to remove the gangue minerals in quartz ore to obtain purified quartz for the preparation of high-purity quartz and the investigation of lattice impurities migration.The results showed that the high-purity quartz with total impurities less than 50μg/g could be obtained from purified quartz after being treated with chlorine at 1200°C.The variation of crystal structure and the lattice impurities migration of quartz during chlorine roasting were studied through in-situ XRD,TGA,SEM-EDS,ICP-MS,FT-IR and XPS analysis.It revealed that the decomposable impurities H_(2)O,-OH,and residual collectors in the crystal of purified quartz could be effectively removed through chlorine roasting above 900°C,which also had an obvious effect on the removal of low-valence trace elements Li,Na and K in the crystal of quartz but didn't affect the multivalent trace elements Al and Ti.This study revealed the removal and migration mechanism of the trace elements in quartz crystal during chlorine roasting.
文摘The aim of this work is to detect electrogenerated hydroxyl radicals and chlorine by simple and less expensive methods. Preparative electrolyses of perchloric acid (HClO4) and sodium chloride (NaCl) were performed on a boron-doped diamond (BDD) electrode. The hydroxyl radicals were quantified indirectly by assaying the samples from the HClO4 (0.1 M) electrolysis with a 10−4 M potassium permanganate solution. The investigations showed that the amount of hydroxyl radicals depends on the concentration of HClO4 and the current density. As for chlorine, a qualitative determination was carried out. A mixture of the electrolyte solution of HClO4 (0.1 M) + NaI (0.2 M) + 2 mL of hexane, taken in this order, leads to a purplish-pink coloration attesting to the presence of Cl2. The same test was carried out with NaBr and NaI giving pale and very pale pink colourations, respectively, showing that the intensity of the colouration depends on the strength of the oxidant present. In addition, oxidants were detected during the electrooxidation of metronidazole (MNZ). The results showed the participation of electrogenerated hydroxyl radicals. The generation of chlorine has also been proven. Furthermore, the degradation leads to a chemical oxygen demand (COD) removal rate of 83.48% and the process is diffusion-controlled.
基金This study was supported by the National Nat-ural Science Foundation of China(No.22379105)the Natural Sci-ence Foundation of Shanxi Province(Nos.20210302123110 and 202303021211059)the Open Fund Project of Ningxia Sinostar Display Material Co.,Ltd.
文摘Although doped hole-transport materials(HTMs)off er an effi ciency benefi t for perovskite solar cells(PSCs),they inevi-tably diminish the stability.Here,we describe the use of various chlorinated small molecules,specifi cally fl uorenone-triphenylamine(FO-TPA)-x-Cl[x=para,meta,and ortho(p,m,and o)],with diff erent chlorine-substituent positions,as dopant-free HTMs for PSCs.These chlorinated molecules feature a symmetrical donor-acceptor-donor structure and ideal intramolecular charge transfer properties,allowing for self-doping and the establishment of built-in potentials for improving charge extraction.Highly effi cient hole-transfer interfaces are constructed between perovskites and these HTMs by strategi-cally modifying the chlorine substitution.Thus,the chlorinated HTM-derived inverted PSCs exhibited superior effi ciencies and air stabilities.Importantly,the dopant-free HTM FO-TPA-o-Cl not only attains a power conversion effi ciency of 20.82% but also demonstrates exceptional stability,retaining 93.8%of its initial effi ciency even after a 30-day aging test conducted under ambient air conditions in PSCs without encapsulation.These fi ndings underscore the critical role of chlorine-substituent regulation in HTMs in ensuring the formation and maintenance of effi cient and stable PSCs.
基金the financial support of the National Natural Science Foundation of China(52162027,52274297 and 52164028)the Hainan Province Science and Technology Special Fund(ZDYF2023SHFZ091)+4 种基金the Hainan Provincial Natural Science Foundation of China(project Nos.221RC540)Hainan Provincial Postdoctoral Science Foundation(project Nos.2022-BH-25)the Collaborative Innovation Center of Marine Science and Technology(Hainan University)the Start-up Research Foundation of Hainan University(KYQD(ZR)2008,23069,23073 and 23067)the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202315)。
文摘High-efficiency seawater electrolysis is impeded by the low activity and low durability of oxygen evolution catalysts due to the complex composition and competitive side reactions in seawater.Herein,a heterogeneousstructured catalyst is constructed by depositing NiFe-layered double hydroxides(NiFe-LDH)on the substrate of MXene(V_(2)CT_(x))modified Ni foam(NF),and abbreviated as NiFe-LDH/V_(2)CT_(x)/NF.As demonstrated,owing to the intrinsic negative charge characteristic of V_(2)CT_(x),chlorine ions are denied entry to the interface between NiFeLDH and V_(2)CT_(x)/NF substrate,thus endowing NiFe-LDH/V_(2)CT_(x)/NF catalyst with high corrosion resistance and durable stability for 110 h at 500 mA cm^(-2).Meanwhile,the two-dimensional structure and high electrical conductivity of V_(2)CT_(x) can respectively enlarge the electrochemical active surface area and guarantee fast charge transfer,thereby synergistically promoting the catalytic performance of NiFe-LDH/V_(2)CT_(x)/NF in both deionized water electrolyte(261 m V at 100 m A cm^(-2))and simulated seawater electrolyte(241 mV at 100 mA cm^(-2)).This work can guide the preparation of oxygen evolution catalysts and accelerate the industrialization of seawater electrolysis.
基金supported by the National Natural Science Foundation of China(Grant No.51708078)Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0815)+2 种基金Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202200542)the Chongqing Innovative Research Group Project(Grant No.CXQT21015)Foundation of Chongqing Normal University(22XLB022).
文摘Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.
文摘This paper presents an engineering system approach using a 2D model of conservation of mass to study the dynamics of ozone and concerned chemical species in the stratosphere.By considering all fourteen photolysis,ozone-generating,and-depleting chemical reactions,the model calculated the transient,spatial changes of ozone under different physical-chemical-radiative conditions.Validation against the measured data demonstrated good accuracy,close match of our model with the observed ozone concentrations at both 20°S and 90°N locations.The deviation in the average concentration was less than 1% and in ozone profiles less than 17%.The impacts of various chlorine-(Cl),nitrogen oxides-(NO_(x)),and bromine-(Br)depleting cycles on ozone concentrations and distribution were investigated.The chlorine catalytic depleting cycle was found to exhibit the most significant impact on ozone dynamics,confirming the key role of chlorine in the problem of ozone depletion.Sensitivity analysis was conducted with levels of 25%,50%,100%,200%,and 400% of the baseline value.The combined cycles(Cl+NO_(x)+Br)showed the most significant influence on ozone behavior.The total ozone abundance above the South Pole could decrease by a small 3%,from 281 DU(Dubson Units)to 273 DU for the 25% level,or by a huge thinning of 60%to 114 DU for the 400% concentration level.When the level of chlorine gases increased beyond 200%,it would cause ozone depletion to a level of ozone hole(below 220 DU).The 2D Ozone Model presented in this paper demonstrates robustness,convenience,efficiency,and executability for analyzing complex ozone phenomena in the stratosphere.
文摘挥发性氯化溶剂被广泛应用在纺织产品生产、加工及后处理过程中,其残留会损害人体健康,破坏环境。在纺织品领域,2020版0eko-tex Standard 100首次将氯化溶剂纳入附录6、附录7,并对其含量和总量做出了限定。如何快速、准确测定纺织品中氯化溶剂残留已经成为业界关注的重点。文中详细介绍了氯化溶剂残留的来源、危害、限量、目前的样品采集方法及检测方法等,并对方法的原理和优缺点进行了分析,可以帮助检测人员找到合适的检验方法,减少实验误差,提高检测能力,为生态纺织品的标准体系建设提供技术支持。
文摘A method was developed for determination of chlorine and bromine in plant materials by ion chromatography using temperature programing-semi molten for sample preparation. Values of detection limits of the method found were 1.0×10^-5 for CI and 1.3×10^-6 for Br. The measuring range of the method found were 0.3-20.0 mg/L for CI and 4,0-120,0 μg/L for Br. The results obtained agreed quite well with those reference values.
