Enhancing catalytic efficiency and selectivity is critical issues for CO_(2) conversion.The rod-like Cu/N co-doped TiO_(2) samples(Cu/N-TiO_(2)) were synthesized by the electrospinning-calcination method.The substitut...Enhancing catalytic efficiency and selectivity is critical issues for CO_(2) conversion.The rod-like Cu/N co-doped TiO_(2) samples(Cu/N-TiO_(2)) were synthesized by the electrospinning-calcination method.The substitutional Cu and interstitial N doping not only enhanced visible-light absorption ability,but also formed the Ti(Ⅲ)sites.The obviously synergistic effect between the photocatalysis and thermalcatalysis appeared for CO_(2) conversion over the 8-Cu/N-TiO_(2) catalyst.After 9 h visible-light-illumination at 160℃,the CO,CH4and O_(2) yields reached 49.7,1455.1 and 2910.2μmol/gcat,respectively.In the 7thcycling,the yields of two main CH4and O_(2) products were slightly down by less than 11.5%,and the selectivity of CH_(4) product kept above 98%.Combined with the theoretical surface mode,Cu/N co-doping could promote the adsorption-ability for H_(2)O and CO_(2) molecules and reduce activation-energy for CO_(2)conversion.Hence,the co-doping construction showed a great significance of designing efficient photothermal catalysts for the CO_(2)conversion application.展开更多
Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the additi...Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SEM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.展开更多
To study the nonlinear phenomena in rod-like magnetic liquid crystals(RMLCs), this paper establishes the dynamic model of molecular motion when giving a twisting disturbance to the molecules under external magnetic fi...To study the nonlinear phenomena in rod-like magnetic liquid crystals(RMLCs), this paper establishes the dynamic model of molecular motion when giving a twisting disturbance to the molecules under external magnetic field.We find the twist of the molecules under magnetic field can be propagated in the form of a traveling wave. The dynamic equation of the molecular twisting we derived satisfies the form of Sine-Gordon equation. We obtain two solutions of the Sine-Gordon equation by theoretical calculation: the kink and anti-kink solitons and breathers. The characteristics of those solitons and breathers are discussed.展开更多
The paper demonstrated a facile approach for the orientated assembly of the rod-like silica particles by sandwich structure from the combined effect of superhydrophobic template and the superhydrophilic substrates. Th...The paper demonstrated a facile approach for the orientated assembly of the rod-like silica particles by sandwich structure from the combined effect of superhydrophobic template and the superhydrophilic substrates. The rod-like particles can be arranged in ring-like, square-like and etc from the confined effect of the template, which will produce an important insight for the oriented assembly ofanisotropic particles and the development of the novel functional materials and devices.展开更多
The rod-like assembly from BAB block copolymer with hydrophilic middle block A in aqueous solution was described. The copolymer used is polystyrene (PS)39-b-poly(4-vinylpyridine)(P4VP)98-b-PS39 (the subscripts are the...The rod-like assembly from BAB block copolymer with hydrophilic middle block A in aqueous solution was described. The copolymer used is polystyrene (PS)39-b-poly(4-vinylpyridine)(P4VP)98-b-PS39 (the subscripts are the average polymerization degree of corresponding blocks) triblock copolymer with Mw/Mn = 1.15. The aggregates were characterized by transmission electron microscopy and atomic force microscopy. The dependence of rod-like aggregate formation on solvents, pH, and polymer concentrations was investigated. The rod-like aggregates were formed when using dioxane as initial solvent, while spherical micelles were formed using DMF. Elevating pH values from 4 to 5 to 7 and decreasing initial copolymer concentrations from 1.5 wt% to 1.0 wt% to 0.5 wt% were favorable for the formation of well-defined rod-like aggregates. In addition, the bicontinuous rods and lamellae were observed when preparing colloid solutions in appropriate conditions.展开更多
A salt-assistant stearic acid method （SAM） capable of forming ultrafine K4Ce2Nb10O30 products was described. XRD pattern re-vealed that tetragonal K4Ce2Nb10O30 products could be obtained by heat treatment at 900 ℃ ...A salt-assistant stearic acid method （SAM） capable of forming ultrafine K4Ce2Nb10O30 products was described. XRD pattern re-vealed that tetragonal K4Ce2Nb10O30 products could be obtained by heat treatment at 900 ℃ for 2 h. Transmission electron microscopy （TEM） observations indicated the introduction of KCl could lead to the formation of rod-like K4Ce2Nb10O30 products. The species of salts played a crucial role in fine tuning the shapes and sizes of K4Ce2Nb10O30 products. Furthermore, the K4Ce2Nb10O30 prepared by salt-assistant SAM had considerable activity under visible light irradiation.展开更多
Rod-like single-phase seed crystals of yttrium-α-SiAlONs were synthesized by combustion synthesis method. The XRD patterns, the morphologies of products and formation mechanism were investigated. The SEM observation ...Rod-like single-phase seed crystals of yttrium-α-SiAlONs were synthesized by combustion synthesis method. The XRD patterns, the morphologies of products and formation mechanism were investigated. The SEM observation of crystals exhibits well developed elongated hexagonal crystals with highly agglomerative features, assigned to pure and well-crystallized α-SiAlON. After special chemical treatments and water washing, the powders are well dispersed and still keep elongated hexagonal crystals, and the XRD pattern shows that the rod-like structure is crystalline yttrium-α-SiAlON with only a trace of β-SiAlON.展开更多
Rutile phase exhibits higher refractive index and h id ing power, good chemical stability, and is becoming a candidate material for the high-temperature separation and catalysis applications. The thermodynamically sta...Rutile phase exhibits higher refractive index and h id ing power, good chemical stability, and is becoming a candidate material for the high-temperature separation and catalysis applications. The thermodynamically stable feature of rutile among the three polymorphs of TiO 2 usually hinders ob taining nano-sized rutile phase by a conventional calcining way. However, acid peptization of amorphous TiO 2 is favorable to the formation of rutile phase. I n this work, well-crystallized and well-dispersed rod-like rutile particles w ith specific surface areas of 49.1 and 35.0 m 2/g were prepared by hydrothermal ly treating the acid peptized TiO 2 amorphous sols at relatively low temperatur es of 200 ℃ or 240 ℃, respectively. The formation of non-touching rutile part icles is attributed to high long-range electrostatic forces between particles i n the presence of the high concentration of the peptizer. The acid peptization w ould easily break the ≡Ti-O-Ti≡ bonds to form ≡Ti-OH or HO-Ti-OH species depending on the amount of acid, and create conditions for the formation of rut ile nuclei after structural rearrangements.展开更多
In-situ rod-like Al2O3 grain was prepared by adding CAS multiphase additives under the sintering condition of 30 MPa, 1 550℃and 1 h.The sintering behaviors,microstructure,toughening mechanism and access of Al2O3 cera...In-situ rod-like Al2O3 grain was prepared by adding CAS multiphase additives under the sintering condition of 30 MPa, 1 550℃and 1 h.The sintering behaviors,microstructure,toughening mechanism and access of Al2O3 ceramics were investigated by SEM,EDS and WDW omnipotent electronic mechanical testing machine,etc,and the crack propagating model of cylindrical crystal/3Y-TZP composite toughening Al2O3 ceramics was established.The results show that the composite additives prompt the anisotropic growth of Al2O3 grain,which strengthens toughening effect of 3Y-TZP in 3Y-TZP/Al2O3 composite ceramics.Moreover, the experimental material density is near to theoretical density,bending strength is 556.35 MPa,and fracture toughness is 6.73 MPa·m1 /2.The mechanical properties of the materials are obviously improved.展开更多
The urea oxidation reaction has attracted increasing attention.Here,porous rod-like Ni2P/Ni assemblies,which consist of numerous nanoparticle subunits with matching interfaces at the nanoscale have been synthesized vi...The urea oxidation reaction has attracted increasing attention.Here,porous rod-like Ni2P/Ni assemblies,which consist of numerous nanoparticle subunits with matching interfaces at the nanoscale have been synthesized via a simple phosphating approach.Density functional theory calculations and density of states indicate that porous rod-like Ni2P/Ni assemblies can significantly enhance the activity of chemical bonds and the conductivity compared with NiO/Ni toward the urea oxidation reaction.The optimal catalyst of Ni2P/Ni can deliver a low overpotential of 50 mV at 10 mA·cm−2 and Tafel slope of 87.6 mV·dec−1 in urea oxidation reaction.Moreover,the constructed electrolytic cell exhibits a current density of 10 mA·cm−2 at a cell voltage of 1.47 V and an outstanding durability in the two-electrode system.This work has provided a new possibility to fabricate metal phosphides-metal assemblies with advanced performance.展开更多
Ba0.85Ca0.15Zr0.10Ti0.90O3(BCZT)lead-free ceramics demonstrated excellent dielectric,ferroelectric,and piezoelectric properties at the morphotropic phase boundary(MPB).So far,to study the effect of morphological chang...Ba0.85Ca0.15Zr0.10Ti0.90O3(BCZT)lead-free ceramics demonstrated excellent dielectric,ferroelectric,and piezoelectric properties at the morphotropic phase boundary(MPB).So far,to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics,researchers have mostly focused on the influence of spherical grain shape change.In this study,BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route.X-ray diffraction(XRD)and selected area electron diffraction(SAED)performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry.Scanning electron microscopy(SEM)image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4.Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric(εr=11,906,tanδ=0.014,Pr=6.01μC/cm^2,and Ec=2.46 kV/cm),and electrocaloric properties(ΔT=0.492 K andz=0.289(K×mm)/kV at 17 kV/cm)with respect to spherical BCZT ceramics.Therefore,rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.展开更多
Directional solidification of rod-like eutectic is an important route to produce in situ composites.The rod-like phase spacing of composites is a crucial parameter in determining the properties of the materials.In thi...Directional solidification of rod-like eutectic is an important route to produce in situ composites.The rod-like phase spacing of composites is a crucial parameter in determining the properties of the materials.In this study,the rod-like phase spacing of melt-grown in situ eutectic composites is estimated by the method that is established based on the classical Jackson-Hunt theory and completed by considering the minimum undercooling principle in eutectic solidification at steady state.The density difference between the solid phases is also considered when calculating the diffusion field in the liquid.It is found that the rod-like phase spacing of in situ eutectic composites is generally a not unique value but displays a finite range under fixed growth conditions.Also,the range width,which decreases with increasing growth rate and vice versa,is only dependent on the intrinsic properties of an alloy at a given growth rate.By comparing with the experimental observations,the results show that the predicted spacings are in reasonable agreement with experimental data for nonfaceted-nonfaceted Succinonitrile-(D)camphor,MnSb-Sb,and Al-Al3Ni alloys and faceted-nonfaceted MnBi-Bi system when growing in a coupled manner.展开更多
基金National Natural Science Foundation of China(No.51802082)Key Scientific and Technological Project of Henan Province(No.222102320100)Program for Science&Technology Innovation Talents in Universities of Henan Province(No.21HATIT016).
文摘Enhancing catalytic efficiency and selectivity is critical issues for CO_(2) conversion.The rod-like Cu/N co-doped TiO_(2) samples(Cu/N-TiO_(2)) were synthesized by the electrospinning-calcination method.The substitutional Cu and interstitial N doping not only enhanced visible-light absorption ability,but also formed the Ti(Ⅲ)sites.The obviously synergistic effect between the photocatalysis and thermalcatalysis appeared for CO_(2) conversion over the 8-Cu/N-TiO_(2) catalyst.After 9 h visible-light-illumination at 160℃,the CO,CH4and O_(2) yields reached 49.7,1455.1 and 2910.2μmol/gcat,respectively.In the 7thcycling,the yields of two main CH4and O_(2) products were slightly down by less than 11.5%,and the selectivity of CH_(4) product kept above 98%.Combined with the theoretical surface mode,Cu/N co-doping could promote the adsorption-ability for H_(2)O and CO_(2) molecules and reduce activation-energy for CO_(2)conversion.Hence,the co-doping construction showed a great significance of designing efficient photothermal catalysts for the CO_(2)conversion application.
基金Funded by the Project of Instituto Politecnico Nacional(SIPIPN-20182176)
文摘Al-doped ZnO(AZO) powders were prepared by using metal chloride precursors and the sol-gel technique. IR peaks observed at 1590 cm-1 and 1620 cm-1indicated the formation of metal chelate as a consequence of the addition of acetylacetone to the metal chloride solution. TG-DSC analysis of the AZO gels confirmed the formation of metal chelate as evidenced by the development of several weight loss peaks accompanied by the introduction of new endothermic peaks. The resulting AZO gels were annealed at 500, 600, and 800 ℃ to study the effect of annealing temperature. XRD and SEM results showed that crystallization of AZO gels takes place around 600 ℃. Hexagonal wurtzite structure was identified as the main phase for all the samples. In addition, small shift of the XRD(002) peak coupled with XPS results from the AZO powders confirmed the successful doping of the ZnO powders. Micron sized rod-like AZO powders were uniform in dimension and morphology and remained stable even at 800 ℃.
基金Supported by the Basic Scientific Research Project of Provincial Colleges and Universities in Heilongjiang Province under Grant No.KJCXZD201723the Youth Science Foundations of Heilongjiang University under Grant No.QL201606
文摘To study the nonlinear phenomena in rod-like magnetic liquid crystals(RMLCs), this paper establishes the dynamic model of molecular motion when giving a twisting disturbance to the molecules under external magnetic field.We find the twist of the molecules under magnetic field can be propagated in the form of a traveling wave. The dynamic equation of the molecular twisting we derived satisfies the form of Sine-Gordon equation. We obtain two solutions of the Sine-Gordon equation by theoretical calculation: the kink and anti-kink solitons and breathers. The characteristics of those solitons and breathers are discussed.
基金financial support by the National Nature Sciences Foundation (Nos.51373183,91127029,and 21074139)973 program (No.2013CB933000)Key Research Program of the Chinese Academy of Sciences
文摘The paper demonstrated a facile approach for the orientated assembly of the rod-like silica particles by sandwich structure from the combined effect of superhydrophobic template and the superhydrophilic substrates. The rod-like particles can be arranged in ring-like, square-like and etc from the confined effect of the template, which will produce an important insight for the oriented assembly ofanisotropic particles and the development of the novel functional materials and devices.
文摘The rod-like assembly from BAB block copolymer with hydrophilic middle block A in aqueous solution was described. The copolymer used is polystyrene (PS)39-b-poly(4-vinylpyridine)(P4VP)98-b-PS39 (the subscripts are the average polymerization degree of corresponding blocks) triblock copolymer with Mw/Mn = 1.15. The aggregates were characterized by transmission electron microscopy and atomic force microscopy. The dependence of rod-like aggregate formation on solvents, pH, and polymer concentrations was investigated. The rod-like aggregates were formed when using dioxane as initial solvent, while spherical micelles were formed using DMF. Elevating pH values from 4 to 5 to 7 and decreasing initial copolymer concentrations from 1.5 wt% to 1.0 wt% to 0.5 wt% were favorable for the formation of well-defined rod-like aggregates. In addition, the bicontinuous rods and lamellae were observed when preparing colloid solutions in appropriate conditions.
基金supported by the National Natural Science Foundation of China (50902070)the Natural Science Foundation of Jiangsu province (BK2009391)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (20093219120011)NUST Research Funding (ZDJH07)
文摘A salt-assistant stearic acid method （SAM） capable of forming ultrafine K4Ce2Nb10O30 products was described. XRD pattern re-vealed that tetragonal K4Ce2Nb10O30 products could be obtained by heat treatment at 900 ℃ for 2 h. Transmission electron microscopy （TEM） observations indicated the introduction of KCl could lead to the formation of rod-like K4Ce2Nb10O30 products. The species of salts played a crucial role in fine tuning the shapes and sizes of K4Ce2Nb10O30 products. Furthermore, the K4Ce2Nb10O30 prepared by salt-assistant SAM had considerable activity under visible light irradiation.
文摘Rod-like single-phase seed crystals of yttrium-α-SiAlONs were synthesized by combustion synthesis method. The XRD patterns, the morphologies of products and formation mechanism were investigated. The SEM observation of crystals exhibits well developed elongated hexagonal crystals with highly agglomerative features, assigned to pure and well-crystallized α-SiAlON. After special chemical treatments and water washing, the powders are well dispersed and still keep elongated hexagonal crystals, and the XRD pattern shows that the rod-like structure is crystalline yttrium-α-SiAlON with only a trace of β-SiAlON.
文摘Rutile phase exhibits higher refractive index and h id ing power, good chemical stability, and is becoming a candidate material for the high-temperature separation and catalysis applications. The thermodynamically stable feature of rutile among the three polymorphs of TiO 2 usually hinders ob taining nano-sized rutile phase by a conventional calcining way. However, acid peptization of amorphous TiO 2 is favorable to the formation of rutile phase. I n this work, well-crystallized and well-dispersed rod-like rutile particles w ith specific surface areas of 49.1 and 35.0 m 2/g were prepared by hydrothermal ly treating the acid peptized TiO 2 amorphous sols at relatively low temperatur es of 200 ℃ or 240 ℃, respectively. The formation of non-touching rutile part icles is attributed to high long-range electrostatic forces between particles i n the presence of the high concentration of the peptizer. The acid peptization w ould easily break the ≡Ti-O-Ti≡ bonds to form ≡Ti-OH or HO-Ti-OH species depending on the amount of acid, and create conditions for the formation of rut ile nuclei after structural rearrangements.
基金Project(2005-11)supported by the Natural Foundation of Heilongjiang Province,ChinaProject(10551306)supported by the Ministry ofEducation of Heilongjiang Province,ChinaProjects(3062,L030)supported by the Science and Research Foundation of JiamusiUniversity,China
文摘In-situ rod-like Al2O3 grain was prepared by adding CAS multiphase additives under the sintering condition of 30 MPa, 1 550℃and 1 h.The sintering behaviors,microstructure,toughening mechanism and access of Al2O3 ceramics were investigated by SEM,EDS and WDW omnipotent electronic mechanical testing machine,etc,and the crack propagating model of cylindrical crystal/3Y-TZP composite toughening Al2O3 ceramics was established.The results show that the composite additives prompt the anisotropic growth of Al2O3 grain,which strengthens toughening effect of 3Y-TZP in 3Y-TZP/Al2O3 composite ceramics.Moreover, the experimental material density is near to theoretical density,bending strength is 556.35 MPa,and fracture toughness is 6.73 MPa·m1 /2.The mechanical properties of the materials are obviously improved.
基金This work was supported by the National Natural Science Foundation of China(Nos.U1904215 and 21671170)the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP),Qinglan Project of Jiangsu and Program for Colleges Natural Science Research in Jiangsu Province(No.18KJB150036)We also acknowledge the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘The urea oxidation reaction has attracted increasing attention.Here,porous rod-like Ni2P/Ni assemblies,which consist of numerous nanoparticle subunits with matching interfaces at the nanoscale have been synthesized via a simple phosphating approach.Density functional theory calculations and density of states indicate that porous rod-like Ni2P/Ni assemblies can significantly enhance the activity of chemical bonds and the conductivity compared with NiO/Ni toward the urea oxidation reaction.The optimal catalyst of Ni2P/Ni can deliver a low overpotential of 50 mV at 10 mA·cm−2 and Tafel slope of 87.6 mV·dec−1 in urea oxidation reaction.Moreover,the constructed electrolytic cell exhibits a current density of 10 mA·cm−2 at a cell voltage of 1.47 V and an outstanding durability in the two-electrode system.This work has provided a new possibility to fabricate metal phosphides-metal assemblies with advanced performance.
基金The authors gratefully acknowledge the generous financial support of CNRST Priority Program(PPR 15/2015)Slovenian Research Agency Program(P1-0125)European Union’s Horizon 2020 Research and Innovation Program under the Marie Skłodowska-Curie Grant Agreement(No.778072).
文摘Ba0.85Ca0.15Zr0.10Ti0.90O3(BCZT)lead-free ceramics demonstrated excellent dielectric,ferroelectric,and piezoelectric properties at the morphotropic phase boundary(MPB).So far,to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics,researchers have mostly focused on the influence of spherical grain shape change.In this study,BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route.X-ray diffraction(XRD)and selected area electron diffraction(SAED)performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry.Scanning electron microscopy(SEM)image showed that BCZT ceramics have kept the 1D rod-like grains with an average aspect ratio of about 4.Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric(εr=11,906,tanδ=0.014,Pr=6.01μC/cm^2,and Ec=2.46 kV/cm),and electrocaloric properties(ΔT=0.492 K andz=0.289(K×mm)/kV at 17 kV/cm)with respect to spherical BCZT ceramics.Therefore,rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.
基金supported by the National Natural Science Foundation of China(Grant Nos.50971102,50201012)the Natural Science Foundation of the Shaanxi Education Committee,China(Grant No.14JK1363)
文摘Directional solidification of rod-like eutectic is an important route to produce in situ composites.The rod-like phase spacing of composites is a crucial parameter in determining the properties of the materials.In this study,the rod-like phase spacing of melt-grown in situ eutectic composites is estimated by the method that is established based on the classical Jackson-Hunt theory and completed by considering the minimum undercooling principle in eutectic solidification at steady state.The density difference between the solid phases is also considered when calculating the diffusion field in the liquid.It is found that the rod-like phase spacing of in situ eutectic composites is generally a not unique value but displays a finite range under fixed growth conditions.Also,the range width,which decreases with increasing growth rate and vice versa,is only dependent on the intrinsic properties of an alloy at a given growth rate.By comparing with the experimental observations,the results show that the predicted spacings are in reasonable agreement with experimental data for nonfaceted-nonfaceted Succinonitrile-(D)camphor,MnSb-Sb,and Al-Al3Ni alloys and faceted-nonfaceted MnBi-Bi system when growing in a coupled manner.
