Flower-like hierarchical three-dimensional Ni Fe layered double hydroxides hollow microspheres(3D NiFe-LDH HMS),as one kind of novel non-noble metal electrocatalysts,have been fabricated in a templatefree route for wa...Flower-like hierarchical three-dimensional Ni Fe layered double hydroxides hollow microspheres(3D NiFe-LDH HMS),as one kind of novel non-noble metal electrocatalysts,have been fabricated in a templatefree route for water oxidation.Both of the concentration of ammonium fluoride and the reaction time are adjusted to obtain a series of Ni Fe-LDH microspheres,with different internal structures from massive to hollow generated during the hydrothermal treatment,which improve the electrocatalytic activity of the Ni Fe-LDH catalysts towards the evolution reaction of oxygen.The optimized Ni Fe-LDH-0.4M HMS show the excellent OER performance in alkaline electrolyte withη=290 mV@10 mA cm^-2,and a Tafel slope of 51 mV dec-1,which outperforms the benchmark RuO2 catalyst.The possible reason is attributed to the more exposure of active sites,and fast ion transport resulting from the hierarchical hollow structure.展开更多
Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high...Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic performance.However,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical stability.Herein,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and hereafter.Using electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic structure.Density functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.展开更多
Incorporation of anions of Acid Red 114 dye （1,3-naphthalenedisulfonic acid, 8-[2-[3,3＇-dimethyl-4＇-[2-[4- [l（4-methylphenyl）sulfonyl]oxy] phenyl]diazenyl] [1,1＇-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium sal...Incorporation of anions of Acid Red 114 dye （1,3-naphthalenedisulfonic acid, 8-[2-[3,3＇-dimethyl-4＇-[2-[4- [l（4-methylphenyl）sulfonyl]oxy] phenyl]diazenyl] [1,1＇-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium salt） （denoted as NPDA） into ZnAl-layered double hydroxides （LDHs） has been carried out by an anion- exchange method in an effort to improve their thermal stability and light fastness. After intercalation of NPDA anions, the interlayer distance of the LDHs increases from 0.87 to 2.18 nm, confirming their incorporation into the interlayer galleries of the LDHs host. Infrared spectroscopy and thermogravimetric analysis revealed the presence of host-vip interactions between LDHs layers and NPDA anions. The thermal stability of NPDA and ZnAI-NPDA-LDHs was compared by thermogravimetric-differential ther- mal analysis, UV-visible spectroscopy and infrared spectroscopy. It was found that the thermal stability of NPDA anions was markedly improved by incorporation into the ZnA1-LDHs matrix, while the light fastness was also enhanced.展开更多
It is of great and increasing interest to develop multifunctional additives to enhance the anti-aging performance of polypropylene(PP)and then enlarge its application fields.Here,a hindered amine light stabilizer(H fo...It is of great and increasing interest to develop multifunctional additives to enhance the anti-aging performance of polypropylene(PP)and then enlarge its application fields.Here,a hindered amine light stabilizer(H for HALS)and a hindered phenolic antioxidant(D for DBHP)with low molecular weight were co-intercalated into layered double hydroxides(LDHs)through a coprecipitation method to produce a series of inorganic–organic hybrid materials Zn2Al-HxDy-LDH,adjusting the anion ratio(x+y=1 and x:y=0:1,1:0,1:1,2:1,1:2).Subsequently,hybrid material LDH fillers(HALS-LDH,DBHP-LDH,HxDy-LDH,and(H-LDH)x(D-LDH)y),used as anti-aging agents,were successively dispersed into PP by two methods:solvent mixing/casting and extrusion mixing.The corresponding crystalline structure,morphological,rheological properties and thermal and light oxidative degradation behaviour were carefully investigated using various techniques such as XRD,TEM and rheology.The results showed that the LDH fillers were well dispersed into PP without any influence on its crystallization behavior and provided a chain extension effect on PP,and this is even more pronounced for HxDy-LDH.The thermal stability of HxDy-LDH/PP composites(x:y=1:1,2:1,1:2)is significantly improved,compared with that of other composites.Moreover,through the accelerated aging test,the co-intercalated hybrid material HxDy-LDH significantly inhibited the oxidative degradation of PP(thermal-aging and light-aging).The concomitant presence of HALS/DBHP co-intercalated within the LDH structure strongly improved the anti-aging performance of PP.Therefore,such a co-intercalated I/O hybrid adaptive system as a multifunctional additive agent opens the pathway for potential future research of high-performance PP associated with hybrid fillers.展开更多
Developing efficient Pt-free electrocatalysts for hydrogen evolution reaction(HER)at all pHs remains challenging for large-scale hydrogen production,especially in alkaline and neutral conditions,because of sluggish wa...Developing efficient Pt-free electrocatalysts for hydrogen evolution reaction(HER)at all pHs remains challenging for large-scale hydrogen production,especially in alkaline and neutral conditions,because of sluggish water dissociation.Herein,the synthesis of novel highly dispersed RuO_(-2) nanoparticles on NiO nanosheet arrays(RuO_(-2)/NiO/NF)with efficient pH-universal HER electrocatalysis via a simple in situ growth and sequential calcination process is reported.The as-prepared RuO_(-2)/NiO/NF nanosheet arrays exhibit outstanding HER performance with overpotentials of 31,66,and 84 mV to deliver 10,100,and 300 mA cm^(-2),respectively,in 1.0 M KOH,outperforming even the commercial Pt/C electrocatalyst.In addition,RuO_(-2)/NiO/NF shows a higher turnover frequency at an overpotential of 100 mV in comparison with Pt/C electrocatalyst.It also requires extremely low overpotentials of 98 mV and 254 mV to afford 300 mA cm^(-2) in 0.5 M H_(2)SO_(4) and 1.0 M PBS-neutral solution,respectively.Moreover,RuO_(-2)/NiO/NF can work at 100 mA cm^(-2) for 200 h with negligible decay in 1.0 M KOH.The splendid HER performance can be ascribed to the 3D nanosheet arrays and highly dispersed RuO_(-2) nanoparticles with richly exposed active sites,favoring the efficient electron and mass transfer to the active sites.展开更多
Five boehmite adsorbents with high percentage of exposed(020)facets and large specific surface area were prepared by the separate nucleation and aging steps(SNAS)method at different rotating speeds,namely B-n(n=rotati...Five boehmite adsorbents with high percentage of exposed(020)facets and large specific surface area were prepared by the separate nucleation and aging steps(SNAS)method at different rotating speeds,namely B-n(n=rotating speeds)from 500 to 1500 rpm of the rotating liquidfilm reactor(RLFR).From 500 rpm to 1500 rpm,both specific surface area and percentage of exposed(020)facets increased by ca.10.8%and 16.9%,respectively.For all the samples,the adsorption behavior followed the pseudo-second order model and Langmuir isotherm model towards Congo red(CR).The B-1500 sample exhibited the best adsorption performance for CR with the maximum adsorption quantity of 1298.3 mg g^(−1) in neutral pH solution because of the smallest average particle size(d=55.6 nm),highest specific surface area(BET=224.42 m^(2)g^(−1)),and highest percentage of exposed(020)facets(55.18%).In particular,the boehmite pellets shaped with the alginate-assisted moulding method showed promising practical applications for the removal of CR in water through afixed-bed adsorption column;for example,ca.600 mL of boehmite pellets including ca.15.0 g of boehmite powder has the removal effciency of 75%in 3500 mL of aqueous solution with 100 mg L^(−1)CR.展开更多
Correction for‘Design,fabrication and anti-aging behavior of a multifunctional inorganic-organic hybrid stabilizer derived from co-intercalated layered double hydroxides for polypropylene’by Qian Zhang et al.,Inorg....Correction for‘Design,fabrication and anti-aging behavior of a multifunctional inorganic-organic hybrid stabilizer derived from co-intercalated layered double hydroxides for polypropylene’by Qian Zhang et al.,Inorg.Chem.Front.,2019,6,2539-2549.展开更多
A series of hierarchical flower-like magnesium oxide(MgO)microspheres were prepared with an ethylene glycol(EG)-assisted route at room temperature using ammonia as a precipitating agent.Effects of the ethylene glycol(...A series of hierarchical flower-like magnesium oxide(MgO)microspheres were prepared with an ethylene glycol(EG)-assisted route at room temperature using ammonia as a precipitating agent.Effects of the ethylene glycol(EG)ratio on the structure,morphology and pore properties were carefully investigated.展开更多
基金supported by the National Natural Science Foundation of ChinaProgramme XU GuangqiProgram for Changjiang Scholars and Innovative Research Team in University (No. IRT1205)
文摘Flower-like hierarchical three-dimensional Ni Fe layered double hydroxides hollow microspheres(3D NiFe-LDH HMS),as one kind of novel non-noble metal electrocatalysts,have been fabricated in a templatefree route for water oxidation.Both of the concentration of ammonium fluoride and the reaction time are adjusted to obtain a series of Ni Fe-LDH microspheres,with different internal structures from massive to hollow generated during the hydrothermal treatment,which improve the electrocatalytic activity of the Ni Fe-LDH catalysts towards the evolution reaction of oxygen.The optimized Ni Fe-LDH-0.4M HMS show the excellent OER performance in alkaline electrolyte withη=290 mV@10 mA cm^-2,and a Tafel slope of 51 mV dec-1,which outperforms the benchmark RuO2 catalyst.The possible reason is attributed to the more exposure of active sites,and fast ion transport resulting from the hierarchical hollow structure.
基金the financial support from the Research Foundation for Talented Scholars of Hainan University(YEAZ22091)the financial supports from the Joint Funds of the National Natural Science Foundation of China(ZK20180055)+1 种基金the Programs for Foreign Talent(G2021106012L)the National Natural Science Foundation of China(22075290)。
文摘Carbon-based N-coordinated Mn(Mn-N_(x)/C)single-atom electrocatalysts are considered as one of the most desirable non-precious oxygen reduction reaction(ORR)candidates due to their insignificant Fenton reactivity,high abundance,and intriguing electrocatalytic performance.However,current MnN_(x)/C single-atom electrocatalysts suffer from high overpotentials because of their low intrinsic activity and unsatisfactory chemical stability.Herein,through an in-situ polymerization-assisted pyrolysis,the Co as a second metal is introduced into the Mn-N_(x)/C system to construct Co,Mn-N_(x)dual-metallic sites,which atomically disperse in N-doped 1D carbon nanorods,denoted as Co,Mn-N/CNR and hereafter.Using electron microscopy and X-ray absorption spectroscopy(XAS)techniques,we verify the uniform dispersion of CoN4and MnN4atomic sites and confirm the effect of Co doping on the MnN_(4) electronic structure.Density functional theory(DFT)calculations further elucidate that the energy barrier of ratedetermining step(^(*)OH desorption)decreases over the 2 N-bridged MnCoN_(6) moieties related to the pure MnN_(4).This work provides an effective strategy to modulate the local coordination environment and electronic structure of MnN_(4) active sites for improving their ORR activity and stability.
基金supported by National Natural Science Foundation of China
文摘Incorporation of anions of Acid Red 114 dye （1,3-naphthalenedisulfonic acid, 8-[2-[3,3＇-dimethyl-4＇-[2-[4- [l（4-methylphenyl）sulfonyl]oxy] phenyl]diazenyl] [1,1＇-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium salt） （denoted as NPDA） into ZnAl-layered double hydroxides （LDHs） has been carried out by an anion- exchange method in an effort to improve their thermal stability and light fastness. After intercalation of NPDA anions, the interlayer distance of the LDHs increases from 0.87 to 2.18 nm, confirming their incorporation into the interlayer galleries of the LDHs host. Infrared spectroscopy and thermogravimetric analysis revealed the presence of host-vip interactions between LDHs layers and NPDA anions. The thermal stability of NPDA and ZnAI-NPDA-LDHs was compared by thermogravimetric-differential ther- mal analysis, UV-visible spectroscopy and infrared spectroscopy. It was found that the thermal stability of NPDA anions was markedly improved by incorporation into the ZnA1-LDHs matrix, while the light fastness was also enhanced.
基金supported by the National Natural Science Foundation of China(21571015,21627813)the Fundamental Research Funds for the Central Universities(JD1716,12060093063)the Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1205).
文摘It is of great and increasing interest to develop multifunctional additives to enhance the anti-aging performance of polypropylene(PP)and then enlarge its application fields.Here,a hindered amine light stabilizer(H for HALS)and a hindered phenolic antioxidant(D for DBHP)with low molecular weight were co-intercalated into layered double hydroxides(LDHs)through a coprecipitation method to produce a series of inorganic–organic hybrid materials Zn2Al-HxDy-LDH,adjusting the anion ratio(x+y=1 and x:y=0:1,1:0,1:1,2:1,1:2).Subsequently,hybrid material LDH fillers(HALS-LDH,DBHP-LDH,HxDy-LDH,and(H-LDH)x(D-LDH)y),used as anti-aging agents,were successively dispersed into PP by two methods:solvent mixing/casting and extrusion mixing.The corresponding crystalline structure,morphological,rheological properties and thermal and light oxidative degradation behaviour were carefully investigated using various techniques such as XRD,TEM and rheology.The results showed that the LDH fillers were well dispersed into PP without any influence on its crystallization behavior and provided a chain extension effect on PP,and this is even more pronounced for HxDy-LDH.The thermal stability of HxDy-LDH/PP composites(x:y=1:1,2:1,1:2)is significantly improved,compared with that of other composites.Moreover,through the accelerated aging test,the co-intercalated hybrid material HxDy-LDH significantly inhibited the oxidative degradation of PP(thermal-aging and light-aging).The concomitant presence of HALS/DBHP co-intercalated within the LDH structure strongly improved the anti-aging performance of PP.Therefore,such a co-intercalated I/O hybrid adaptive system as a multifunctional additive agent opens the pathway for potential future research of high-performance PP associated with hybrid fillers.
基金supported by the National Key Research and Development Program of China(2022YFA1503400,2016YFB0301600)National Natural Science Foundation of China(21627813).
文摘Developing efficient Pt-free electrocatalysts for hydrogen evolution reaction(HER)at all pHs remains challenging for large-scale hydrogen production,especially in alkaline and neutral conditions,because of sluggish water dissociation.Herein,the synthesis of novel highly dispersed RuO_(-2) nanoparticles on NiO nanosheet arrays(RuO_(-2)/NiO/NF)with efficient pH-universal HER electrocatalysis via a simple in situ growth and sequential calcination process is reported.The as-prepared RuO_(-2)/NiO/NF nanosheet arrays exhibit outstanding HER performance with overpotentials of 31,66,and 84 mV to deliver 10,100,and 300 mA cm^(-2),respectively,in 1.0 M KOH,outperforming even the commercial Pt/C electrocatalyst.In addition,RuO_(-2)/NiO/NF shows a higher turnover frequency at an overpotential of 100 mV in comparison with Pt/C electrocatalyst.It also requires extremely low overpotentials of 98 mV and 254 mV to afford 300 mA cm^(-2) in 0.5 M H_(2)SO_(4) and 1.0 M PBS-neutral solution,respectively.Moreover,RuO_(-2)/NiO/NF can work at 100 mA cm^(-2) for 200 h with negligible decay in 1.0 M KOH.The splendid HER performance can be ascribed to the 3D nanosheet arrays and highly dispersed RuO_(-2) nanoparticles with richly exposed active sites,favoring the efficient electron and mass transfer to the active sites.
基金supported by National Key R&D Program of China(No.2016YFB0301600)the National Natural Science Foundation of China(21627813)+1 种基金the Fundamental Research Funds for the Central Universities(JD1716,12060093063)Distinguished Professor of Kunlun Scholars in Tarim University.
文摘Five boehmite adsorbents with high percentage of exposed(020)facets and large specific surface area were prepared by the separate nucleation and aging steps(SNAS)method at different rotating speeds,namely B-n(n=rotating speeds)from 500 to 1500 rpm of the rotating liquidfilm reactor(RLFR).From 500 rpm to 1500 rpm,both specific surface area and percentage of exposed(020)facets increased by ca.10.8%and 16.9%,respectively.For all the samples,the adsorption behavior followed the pseudo-second order model and Langmuir isotherm model towards Congo red(CR).The B-1500 sample exhibited the best adsorption performance for CR with the maximum adsorption quantity of 1298.3 mg g^(−1) in neutral pH solution because of the smallest average particle size(d=55.6 nm),highest specific surface area(BET=224.42 m^(2)g^(−1)),and highest percentage of exposed(020)facets(55.18%).In particular,the boehmite pellets shaped with the alginate-assisted moulding method showed promising practical applications for the removal of CR in water through afixed-bed adsorption column;for example,ca.600 mL of boehmite pellets including ca.15.0 g of boehmite powder has the removal effciency of 75%in 3500 mL of aqueous solution with 100 mg L^(−1)CR.
文摘Correction for‘Design,fabrication and anti-aging behavior of a multifunctional inorganic-organic hybrid stabilizer derived from co-intercalated layered double hydroxides for polypropylene’by Qian Zhang et al.,Inorg.Chem.Front.,2019,6,2539-2549.
基金supported by National Key R&D Program of China(No.2016YFB0301600)the National Natural Science Foundation of China,and the Fundamental Research Funds for the Central Universities(12060093063).S.Ahmed specially thanks the financial support from Chinese Scholarship Council.
文摘A series of hierarchical flower-like magnesium oxide(MgO)microspheres were prepared with an ethylene glycol(EG)-assisted route at room temperature using ammonia as a precipitating agent.Effects of the ethylene glycol(EG)ratio on the structure,morphology and pore properties were carefully investigated.
